Main trade-off
Sunseeker S4
Its smaller area rating and grass exclusions can rule it out despite the LiDAR advantage.
Head-to-head
Sunseeker S4 vs Sunseeker X3 Plus: S4 avoids an antenna in shade but excludes Zoysia and St. Augustine
The short answer
Choose S4 for a compatible shaded lawn below quarter acre when installing an RTK antenna is awkward. Choose X3 Plus for a mostly open lawn between quarter and three-tenths acre. Check grass type first. Sunseeker’s S4 guidance excludes Zoysia and St. Augustine.
Before you choose
The reasoning and the trade-offs
A modestly larger lawn can rule out the newer navigation choice
A 0.28-acre lawn is about 12 percent above S4’s rating but below X3 Plus’s limit. Better tree-cover navigation does not override the area limit. On that lawn, choose X3 Plus only if RTK placement works, or consider a larger LiDAR mower.
What this is based on
Sunseeker S4: 0.25-acre rating. 0.28 / 0.25 - 1 = 12 percent. Sunseeker X3 Plus: 0.3-acre rating with RTK installation.
Main trade-off
Sunseeker X3 Plus
RTK placement, daytime-only operation and a lower slope limit reduce flexibility.
Sunseeker S4
- Choose it for
- The lawn is below quarter acre with dense tree cover
- You want LiDAR without an RTK antenna
- Main trade-off
- Its smaller area rating and grass exclusions can rule it out despite the LiDAR advantage.
Sunseeker X3 Plus
- Choose it for
- The lawn exceeds quarter acre but stays below 0.3 acre
- A clear-sky RTK installation is practical
- Main trade-off
- RTK placement, daytime-only operation and a lower slope limit reduce flexibility.
About this comparison
Sunseeker S4 vs X3 Plus for a small yard. Compare tree cover, grass exclusions, slopes and the daytime schedule before choosing a navigation system.
Winner by situation
Start with what you need it to do
A shaded 0.2-acre lawn with compatible grass
S4 avoids the RTK antenna. Check geometry and boundaries.
- Sunseeker S4
- Better fit
- Sunseeker X3 Plus
- Depends
An open 0.28-acre lawn
X3 Plus is within its rating. S4 is over its limit.
- Sunseeker S4
- Not suitable
- Sunseeker X3 Plus
- Better fit
A 35 percent interior bank
S4 passes the headline slope threshold only if turf and installation also fit.
- Sunseeker S4
- Depends
- Sunseeker X3 Plus
- Not suitable
A Zoysia lawn
The S4 exclusion is explicit. Verify X3 Plus turf suitability rather than assuming it.
- Sunseeker S4
- Not suitable
- Sunseeker X3 Plus
- Depends
What matters in practice
The differences that matter
A modestly larger lawn can rule out the newer navigation choice
A 0.28-acre lawn is about 12 percent above S4’s rating but below X3 Plus’s limit. Better tree-cover navigation does not override the area limit. On that lawn, choose X3 Plus only if RTK placement works, or consider a larger LiDAR mower.
How we reached this conclusion
Sunseeker S4: 0.25-acre rating. 0.28 / 0.25 - 1 = 12 percent. Sunseeker X3 Plus: 0.3-acre rating with RTK installation.
A two-hour free-lawn window changes how the cycle feels
Starting fully charged, the stated S4 cycle pauses after about 90 minutes. X3 Plus claims up to 120 minutes before recharge. If mowing must finish before children use the lawn, that difference is relevant, though neither claim guarantees the yard will be complete.
How we reached this conclusion
Sunseeker S4: 90-minute mowing claim, 80-minute charging claim. Sunseeker X3 Plus: 120-minute mowing claim, 90-minute charging claim. Daytime operation required.
A slope pass can still fail the grass check
S4’s 42 percent slope rating makes it the candidate for a 35 percent interior bank, while X3 Plus stops at 30 percent. But S4’s explicit grass exclusions still apply. A matching slope number cannot turn an excluded turf type into a recommendation.
How we reached this conclusion
Sunseeker S4: 42 percent interior slope claim and named grass exclusions. Sunseeker X3 Plus: 30 percent interior slope claim. No exemption from turf checks inferred.
Try your real numbers
Will either mower clear your yard constraints?
The result checks hard limits only. Preferences stay out of the calculation.
Sunseeker S4
Fits these inputsRated for 0.25 acre and 42% interior grade, with wire-free setup. Your input is 0.25 acre and 20% grade.
Sunseeker X3 Plus
Fits these inputsRated for 0.3 acre and 30% interior grade, with wire-free setup. Your input is 0.25 acre and 20% grade.
The area check uses the published maximum without adding a reserve. Where a systematic mowing rating is shown, that pattern is required for the maximum area. Boundary slopes can have a lower limit than interior ground. Trees, gates and disconnected zones still need checking.
Choice A
Sunseeker, S4
S4
A quarter-acre LiDAR mower that avoids an RTK antenna, with important grass-type and boundary restrictions to check before choosing it.
- Best matched use
- The lawn is below quarter acre with dense tree cover
Checked facts
- Rated lawn size: 0.25 acre
- Navigation: LiDAR and vision, no RTK antenna
- Interior slope limit: 42 percent
- Mow and charge claims: 90 minutes mowing, 80 charging
Choice B
Sunseeker, X3 Plus
X3 Plus
A three-tenths-acre RTK and vision mower for a mostly open small lawn, with daytime mowing and a 3.2-inch cutting ceiling.
- Best matched use
- The lawn exceeds quarter acre but stays below 0.3 acre
Checked facts
- Rated lawn size: 0.3 acre
- Navigation: RTK and vision
- Interior slope limit: 30 percent
- Mow and charge claims: 120 minutes mowing, 90 charging
Meaningful differences
What changes the fit
| What changes | Sunseeker S4 | Sunseeker X3 Plus | Why it matters |
|---|---|---|---|
| Rated lawn size | 0.25 acre | 0.3 acre | The higher navigation tier is not the larger area rating. |
| Navigation | LiDAR and vision, no RTK antenna | RTK and vision | Tree cover and antenna placement can outweigh the area difference. |
| Interior slope limit | 42 percent | 30 percent | A 35 percent interior bank changes the choice, subject to all other installation limits. |
| Mow and charge claims | 90 minutes mowing, 80 charging | 120 minutes mowing, 90 charging | These describe individual cycles, not a guaranteed whole-yard completion time. |
| Grass and daylight | US guidance excludes Zoysia and St. Augustine | FAQ specifies daytime operation | Check turf suitability and the times the lawn is free of people and pets. |
What you give up
Every choice has a cost
If you choose Sunseeker S4
- An 80 cm minimum passage does not fit a 30-inch gate.
If you choose Sunseeker X3 Plus
- The 30 percent slope limit is lower than Sunseeker’s S4.
Recommendation switch
The decision flips if...
The lawn is below quarter acre with dense tree cover
Choose Sunseeker S4. You want LiDAR without an RTK antenna
The lawn exceeds quarter acre but stays below 0.3 acre
Choose Sunseeker X3 Plus. A clear-sky RTK installation is practical
What the facts say
What the comparison shows
Useful conclusions from the current robotic lawn mowers comparison, followed by the checked facts used to reach them.
See the checked facts and calculation notes
| Product | Needs matched | Checked facts | Source records |
|---|---|---|---|
| Sunseeker S4 |
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| Sunseeker X3 Plus |
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Ready to choose?
Check the price. Read the owner reviews.
Open either model on Amazon to check the current price, customer reviews and delivery options.
Sunseeker S4
The lawn is below quarter acre with dense tree cover
See price & reviews on AmazonSunseeker X3 Plus
The lawn exceeds quarter acre but stays below 0.3 acre
See price & reviews on AmazonLinks open in a new tab.