A straight answer to the only question that matters before you spend four figures: which model actually fits your property?
Most robot buying guides are brand brochures. This one isn't. It's organized around the four or five facts about your yard or pool that determine the right machine — and where we think you should spend less, we say so.
A note on brands. You'll see Sunseeker most often in the mower section below. That's deliberate: it's the one range we stock in depth across every size band from 0.3 to 6 acres, and the only line that pairs 70% slope capability and Vision AI obstacle avoidance with commercial 4WD at the top end. Where a Kress, Husqvarna or Nexmow is the better answer for your situation, we say so.
Part 1 — Robotic Lawn Mowers
Question 1: How much grass do you actually have?
Not lot size. Mowed area. A half-acre lot with a house, driveway, deck and beds on it is often only 0.2 acres of grass. Getting this wrong is the single most common sizing mistake.
How to measure it in two minutes: open Google Maps, right-click your lawn, choose "Measure distance," and click around the perimeter of the grass only. Google gives you square feet. Divide by 43,560 for acres.
| Your mowed area | What we'd put on it |
|---|---|
|
Up to 0.3 acre (under ~13,000 sq ft) |
Sunseeker X4 (0.3) — 360° LiDAR, wire-free, no antenna to site Also: Kress KR161 (0.25) |
| 0.3 – 0.5 acre |
Sunseeker X5 Gen 2 (0.5) — AWD, RTK + Vision AI 2.0 Also: Kress KR172 (0.5) |
| 0.5 – 1 acre |
Sunseeker X7 Gen 2 (0.75) — AWD, dual cutting disc, 70% slope Also: Kress KR173 (0.75) |
| 1 – 2 acres |
Sunseeker X7 Plus Gen 2 (1.5) — same dual-disc and 70% slope, plus 4G anti-theft Also: Kress KR174 (1.25) · Husqvarna Automower 550H (1.25) · Nexmow M1 (1.25) · Ambrogio L350i Elite (1.75) |
| 2 – 3 acres |
Sunseeker X9 (3) — true 4WD, 42V commercial battery, IPX6, anti-theft Also: Kress KR233 RTKn (3) · Husqvarna Automower 550H EPOS (2.5) · 550 EPOS (2.5) |
| 3+ acres / commercial |
Sunseeker X9 Plus (6) — everything the X9 has, double the coverage, faster charging, edge trimmer included Also: Nexmow M2 (6) · Kress KR236 (6), KR236S Mega (6), KR237 (7) |
Leave yourself headroom. Published acreage ratings assume near-ideal conditions: open ground, simple shape, moderate growth. Slopes, narrow passages, trees and complex borders all reduce real-world coverage. If your lawn lands within about 15% of a model's ceiling, move up one tier. An undersized mower doesn't fail — it just never finishes, and you'll spend the season frustrated.
Question 2: How steep is it?
Slope is the second most common reason a mower disappoints. Stand at the bottom of your worst slope: if it feels like work to walk up, it's probably over 30%.
- Gentle (under 30%) — any model in your size class handles this.
- Moderate to steep (30–45%) — go all-wheel drive: Sunseeker X5 Gen 2, X7 Gen 2 or X7 Plus Gen 2.
- Severe (up to 70%) — the Sunseeker X7 Gen 2 and X7 Plus Gen 2 are rated to 70% slope, which is as steep as anything in this category will climb. For steep and large, the Sunseeker X9 and X9 Plus add true 4WD on a 42V commercial system.
Question 3: Is your lawn one piece, or several?
If your front and back yards are separated by a driveway, fence or path, you need a mower that can hold multiple mapped zones. Every wire-free RTK model here can — but it matters how they get there:
- Wire-free (RTK / GPS / LiDAR) — you walk the boundary once in an app. No wire to bury, easy to change later. This is the entire Sunseeker and Kress range.
- Boundary wire — the Husqvarna Automower 550H (non-EPOS) is wire-guided. Cheaper up front, but installation is real work and changes mean re-running wire.
If your zones are separated by anything the mower can't drive across, it will need to be carried between them, or you'll need a unit per zone. Worth knowing before you buy.
Question 4: What's in the way?
Kids' toys, hoses, pets, garden beds, low furniture. If your lawn is rarely clear, pay for obstacle avoidance — it's the difference between a robot you trust unsupervised and one you follow around.
- Vision AI 2.0 (binocular + iToF cameras) — Sunseeker X5 Gen 2, X7 Gen 2, X7 Plus Gen 2, X9, X9 Plus
- 360° LiDAR — Sunseeker X4
- OAS obstacle avoidance — Kress KR174, KR233, KR236, KR237
One more thing: theft
These machines sit outside, unattended, visible from the street. If that worries you, choose a model with 4G connectivity and anti-theft tracking: Sunseeker X7 Plus Gen 2, X9, X9 Plus, or Nexmow M1 and M2.
Part 2 — Robotic Pool Cleaners
Question 1: How long is your pool?
For a corded cleaner, this is the whole ballgame. The cord has to reach the farthest point of the pool from your outlet, plus slack for the robot to maneuver and climb. Short cord means uncleaned corners — permanently.
| Pool length | Models rated for it |
|---|---|
| Up to 33 ft | Hayward R110 · Polaris 7000 (40 ft cord) · BWT Advanced Pro 100 (49 ft cord) |
| Up to 40 ft | Polaris EPIC 8520 (50 ft cord) · BWT Advanced Pro 150 (53 ft cord) |
| Up to 50 ft | Hayward R130 · Polaris EPIC 8640 (60 ft swivel cord) · Polaris Alpha iQ (60 ft swivel) |
| Up to 60 ft | BWT Advanced Pro 250 (60 ft) · BWT Advanced Pro 600 · Polaris Epic 8642 iQ (60 ft) · Polaris Alpha iQ+ (70 ft) · Hayward TigerShark QC (55 ft) · Maytronics Dolphin Wave 60 (60 ft) |
| Over 60 ft / commercial | Maytronics Dolphin Wave 80 · Wave 100 · Wave 140 (140 ft cord, 5-hour cycle) · BWT Aquabot Nova |
A swivel in the cord is worth paying for. Without one, the cable twists over a cleaning cycle and eventually the robot is tethering itself in circles instead of covering the pool.
Question 2: In-ground or above-ground?
Not interchangeable. An in-ground cleaner in an above-ground pool can damage the liner or simply fail to climb the wall.
- Above-ground (and in-ground) — Polaris 7000 · BWT Advanced Pro 100, 150, 250 · Hayward R110, R130 · Maytronics Dolphin Explorer E50
- In-ground only — the Polaris EPIC and Alpha iQ series, Freedom series, all pressure-side models, Hayward TigerShark QC, Maytronics Explorer E20 and the Wave commercial series
Question 3: Floor only, or floor, walls and waterline?
This is where you can honestly save money. Floor-only cleaners cost meaningfully less, and if your debris is heavy sand and silt that settles on the bottom, that's all you need.
- Floor only — Polaris 7000 · BWT Advanced Pro 100 · Polaris Alpha iQ
- Floor and wall — Polaris 7240 Sport · Maytronics Dolphin Explorer E20 · Maytronics Dolphin Wave 60
- Floor, wall and waterline — Polaris EPIC 8520, 8640, Epic 8642 iQ, Freedom, Freedom Plus · BWT Advanced Pro 150, 250 · BWT Cosmy 250 Omni · Hayward R110, R130 · Maytronics Dolphin Wave 80, Wave 100
You want waterline cleaning if you get a scum line — sunscreen, oils, pollen. No floor cleaner will ever touch that.
Question 4: Corded, cordless, or pressure-side?
Three different machines, often shelved together. The differences are real:
- Corded (plug-in) — unlimited runtime, strongest suction, best filtration. The cord is the tradeoff. This is the right default for most pools.
- Cordless (battery) — no cord to tangle, no cord to trip over, easy to drop in and lift out. Limited by runtime per charge, so it suits small and mid-size pools best. Polaris Freedom, Freedom Plus · AquaClean 1000 Pro, 1500 Pro.
- Pressure-side — runs off your pool's plumbing and requires a separate booster pump. Excellent on heavy leaf loads because debris goes into a large bag, not a small canister. If you do not already have a booster pump installed, do not buy one of these without pricing the pump and installation first. Polaris TR35P, TR36P, Quattro Sport, Quattro Trax.
Question 5: Heavy leaves?
If you're under oaks or pines, filtration capacity matters more than suction specs. A cleaner that fills its canister in ten minutes is a cleaner you empty four times a cycle. Look at the pressure-side models with debris bags (Polaris Quattro Trax, TR36P) or commercial units with cassette and bag filtration (BWT Aquabot Nova, Maytronics Wave series).
For surface debris specifically, a Maytronics Dolphin Skimmi solar skimmer runs on the surface and pulls leaves out before they sink. It complements a floor cleaner — it doesn't replace one.
Still not sure?
Tell us your mowed square footage and worst slope, or your pool's length, shape and what ends up in it, and we'll tell you which model we'd put on our own property — including when the cheaper one is the right answer.
Every purchase includes a complimentary 30-minute setup consultation with a product specialist, so you're not unboxing a $3,000 machine alone.