After completely disassembling my maytronics robot the only I can say is that the design might be simplistic but the thing is meant to fail. The brushed motors that they use have a very limited life span before needing repairs (mostly the pump motor) and the lid that closes the motor box is not sturdy and falls not short of weak points around the o-ring where it can break (and it did in my case).
I don't know if any of the Maytronics model uses brushless motors because, although super important, that's not a piece of information they normally publish nor something that most of the people is going to check. In any case, I'm sure that if they had a brushless motor model it's going to be in the thouthands of dollars range.
I can not tell about other bands because I have no experience with anyone, but I just ordered a refurbished Rapids 2500 from BWT's refurbished site. Time will tell how durable it is.