The most striking thing I learned about robotic lawn mowers: How the mower maps is important. Originally, these mowers all used buried wire to define boundaries that the robots couldn’t cross. Then RTK (which stands for “Real Time Kinematic positioning”—essentially GPS with some added localization data) allowed humans to define the boundary without wires by simply walking the robot around the perimeter of the yard during setup, as long as the robot was in line of sight of the RTK tower. Now Ecovacs has tried something new with the GOAT GX-600 ($999): It simply uses LiDAR to determine where to mow and where not to mow. (LiDAR is what robot vacuums use.)

The problem is, it doesn’t work. Despite trying the GOAT on multiple different lawn setups, I could never get it to work even once. It didn’t see the entire lawn, often mowed the same area back and forth multiple times instead of moving to a new area, ignored boundaries like sidewalks, and refused to cross boundaries it was supposed to cross, like walking paths. Plus, it got stuck so often, even on flat, freshly mowed grass, that it’s hard to imagine ever feeling confident enough to let the GOAT operate autonomously, which is the whole point of a robot.

This is actually the third iteration of the GOAT, and while the v1 and v2 versions of the GOAT seem to have had more success based on early reviews, they appear to be no longer available. The GX-600 was the easiest robot mower to assemble of all the ones I tested. The entire charging base comes pre-assembled, as does the robot. There are no extra parts, wires, or RTK towers: you simply plug it in and send the robot out to scout your lawn. The plastic base and robot were both light enough to move around (which I did a lot).

It took a few tries to get the GOAT to pair with the app, but it was still easy enough to do in under 10 minutes by powering the robot off and on again. In the case of most lawn mower apps, you can access many settings through the app interface whether the mower is online or not. In the case of the Ecovacs, you can only access these settings if the mower is online. Once it is, you can connect via Bluetooth or Wi-Fi, with some actions requiring Bluetooth. Most actions are set on the robot itself, such as adjusting the lawn height. From the app, you can set schedules and decide to operate the robot in automatic or manual mode. Manual mode is code for “remote control,” a feature that is easier to find in other apps. I frequently had trouble connecting to the robot via Bluetooth, even when I was only 10 feet away, and it is a requirement for manual mode. I had to use manual mode a lot on the GOAT to try to move it out of an area where it was having issues, and I had trouble connecting and maintaining that connection.