It seems that a bunch of iRobot's patents must have timed out, given the glut of these similar-but-different, weirdly named robovacs that have appeared recently. I suspect that many share the same components.
We bought the Eufy 11 at around this price from the Mothership a few months ago when it was the Deal of the Day (as opposed to the Daily Deal, if you know what I mean, and I think you do). That one has been pretty good. It has two side brushes and I *think* this only has one; it also has a HEPA filter which this does not seem to -- it's interesting to me that none of the photos you can find of this one show the business end. That one doesn't have a display like this (other than the multicolored status LED), doing all its communication via beeps. I do wonder if the logic is canned or if every one of these vendors is rolling their own; Eufy eventually gets the job done but isn't exactly smart about it.
I was never able to justify the $500-800 for a Roomba, but at <$150, these seem to have good value; even if it only lasts the warranty period it's around $.40/day which seems like slave wages even for a fairly brain-damaged slave that only does vacuuming. (It's also one of the few things I would spring for an extended warranty for, given the combination of unproven brand name, rechargeable batteries, and mechanical complexity. Not sure if you can do that here or not.)