UPDATE - I have now had these for a little over 2 months and I want to expand my review after a bit of experience with them.
GENERAL PERFORMANCE
For reference, I have two cats. There are often cat-hair tumbleweeds hiding in the corners of my home but for the most part I have always felt that I kept a good handle on sweeping and then vacuuming. That was... before I bought the Yeedi's. The first day we got the Yeedi running it ran for about 45 minutes on almost no charge. I am an impatient rebel and I didn't follow the directions to charge it BEFORE using it the first time, and I was impressed it ran that long straight from the box. I was also impressed (and pretty embarassed) by how much stuff came out of the first run. So much fur and other stuff. Even if I run it every few days, the bin almost always looks the same. Full of hair and dust. It is wild!
SPECIFICS ON FUNCTIONALITY/TECHNOLOGY
This particular model does not learn your room dimensions. There are drop sensors which allow it to function without falling off the staircase or the ledge in my living room, but it will not remember where those ledges are. The drop sensors work very well and the Yeedi will tell you if you need to clean them off to make sure they continue to function properly.
For this price I really can't complain though because in the end, if you set it on random and allow it to run until the battery needs recharging, it truly will get the majority of the area. It doesn't really matter that it doesn't memorize the room dimensions. There are two options for running the Yeedi - you can either press the button on the unit or use the app. The app itself is pretty basic - it allows you to select AUTO (random), Edge, or Spot clean. If you press the button on the Yeedi itself, it just starts a Random clean. Edge clean is good to start with because it tries to stay along the edges of a room. Ideally I like to start with Edge clean and then once it has gone around once or twice I change it to Random mode. Most times I just use Random for the entire clean though.
Most of the time I try to run it when I can babysit it... because it can get "caught" on wires or socks or anything you forget you left out. Now, it really doesn't get stuck or tangled but it thinks it is. I have tried to prop up my wires and I am conscious to pick up items from the floor that it can get caught on but it happens. Very easy to fix just lift it up and remove the wires or whatever is "caught" but the good thing is these are so small it is not the same as actually sucking up a sock or a wire getting tangled in a full-size vacuum. THAT is a nightmare, this is easy because nothing actually goes into the unit itself.
When the battery is low the Yeedi will try to guide itself back to the charging station. It can only sense the charger from a certain distance, so sometimes it struggles a bit because it is just too far from the charger to know where it is. If you are using it for several rooms like me, sometimes it will wander around for a long time before it ends up close enough to the charging station to actually sense it. If I am home I will help it out and place it back on the charger myself or close to it so it can find its own way. I did run it the other day while I wasn't home though and it did eventually get itself back there on its own.
ANY NEGATIVES?
These are minor but there are only a few things that I dislike about the Yeedis. Firstly when you grab the basin to empty it I noticed there really isn't a great place to hold it so that you don't pinch your fingers when you close it back up. Weird but now I know to be conscious of where I grip the basin when I close it back up. Second, when you remove the basin to clean, there always ends up being a bit of dirt and dust left underneath the unit. It isn't a big deal because it will get cleaned the next time you run it but it is there. Third it doesn't do the best job at cleaning in corners. Even though it detects them, sometimes it kind of stays too far away to really get into the corner. The brushes would definitely allow it to get right in there but sometimes it just kind of ignores or avoids the corners.