I used to use a Barracuda G3 cleaner and last year I dumped the Barracuda for a Maytronics Active 20. The Active 20 worked reasonably well, but the wall cleaning was really disappointing. It would rarely manage to climb the wall all the way to scrub the tiles, instead slipping off the wall and back down most of the time, only cleaning the tiles in occasional spots here and there.
Anyway, I never took the battery powered vacuum cleaners very seriously until I heard forum members talking about the Aiper Scuba S1 and giving it similar plaudits to the Betta. I considered getting the S1, but I have a kidney-shaped hopper bottom pool and the complaints about the S1 sometimes having difficulty with that kind of pool was a real concern.
During my research I found the Wybot C1, which seemed to be more or less in a similar class, less expensive than an S1, and the reviews didn't seem to complain about pool shape or slope, so I figured for $400, I might as well take a chance.
In short, it wildly exceeded my expectations. It completely blows away the much more expensive Active 20 at wall climbing and waterline scrubbing. It's not even close. It'll climb the wall until it's vertical a couple feet below the water line, pause, and then the impeller will appear to kick into high gear to increase traction and then it'll go right on up to the surface and get to work. It has a dedicated wall mode where it'll just scoot to the right and repeat around the perimeter of the pool.
It cleans the bottom just fine, and it does a much better job than the Active 20 at climbing steps and cleaning them as well (though brushing steps is still a good idea either way). No issues whatsoever climbing from the deep end to the shallow end of the pool.
The basket is roughly similar to the Active 20 with a hinged bottom. You can't swap out the mesh sides but it has a much better no-return flap than the Active 20 does, so it appears to be better at sucking up leaves where the Active 20 sometimes sucks them up and sometimes pushes them around. I'll follow up in the fall when leaf pickup will be a lot more challenging. There is no fine pleated filter mesh option like the Active 20, so that's a point in Maytronics' favor. Putting the basket back in the robot is a little bit fussy until you get used to the right angle to use. Once you have that down, it's fine.
The app is mandatory if you want to change settings, so something to think about there if you have an aversion to apps. Speaking of which, there are a variety of modes and patterns (different wall patterns, different floor patterns) to select from so you can find whatever works best for your situation. You can even select from a variety of pool shapes and materials in the app, but I'm not sure if the pool characteristics actually affect the robot at all. The app can sometimes be a bit fussy in that it's sometimes confusing about whether the robot picked up the mode switch or not. My advice is to set the desired cleaning mode and pattern, wait for the app to say "Successfully Sent!" and then let it get to work - but double check to see that the robot is behaving consistently with the requested mode.
One very nice feature the app provides is "scheduled cleaning". The robot will set aside 120 minutes of its 150 minute putative run time and split it up across 2,3, or 7 days for floor cleaning only (no walls). This is a really fantastic feature and since the robot is cordless, it's much more practical to leave the robot in the pool 24/7 - no ugly tangled cords running around the pool and the Betta and C1 coexist peacefully throughout the week. The pool has never been this clean day after day with minimal effort on my part before. I typically use 3-day mode and bring up the robot to charge in the middle of the week when I get back from work before dropping it back in the next morning.
Unfortunately, these schedules are "take it or leave it" - you can't tailor the timing or run time at all. For example, the 7 day schedule cleans every other day for 30 minutes, but you can't ask it to clean for a consecutive four days at 30 minutes a day, something I would have appreciated, or five days skipping only one day somewhere in between.
The robot is supposed to park itself at the waterline when it's done to be easily picked up, it doesn't seem to be very well implemented. You don't get any notification on your phone that it's done and ready to be picked up so in practice I just find the robot parked at the foot of the wall.
Charging is a piece of cake - you just unscrew a cap on the top of the robot and plug in the charger. There's nothing tricky or difficult about taking off the cap or putting it back on - it works exactly like you'd imagine it should. The charger wires are a little too thin IMHO and easily strained - mine came with a pretty good bend right at the edge of the strain relief and this made me a little worried about the longevity of the wire. Also replacement chargers are very expensive from Wybot - somewhere around $80-100 IIRC. Speaking of which, Wybot doesn't seem to carry much in the way of parts, so if the robot dies out of warranty, it may be hard to keep it in service. That's less of an issue considering the reasonable price, but it would be a shame to throw out a whole robot for want of a small part sometime down the road.
Overall, as long as the longevity is there, my impression is that the Wybot C1 is amazing for the price. If it only had filter mesh as nice as the Active 20 I'd really question if the Maytronics robot serves a purpose at all anymore. I've never used or seen an Aiper Scuba S1 in use so I can't say how the Wybot compares to that, but since it climbs the slopes of my pool fine, at least in terms of performance and navigation it appears to be a good alternative for folks with hopper bottoms and freeform shapes.
Hopefully this is helpful for folks looking in this space. If anyone has any questions I'll respond as best as I can as time permits.
