If you're like me you're confused and a little overwhelmed by all the options for robot vacuums.After a lot of reading I figured out some things:Price differences: why is there such a price difference, under $200 , $400, $ 800... what's the difference?! One of the major differences is that the higher end models map out your house layout, when the battery runs low they go recharge themselves, and once charged, go back to the last spot they were and continue cleaning. The 'lower end' models vacuum randomly, the don't remember where they've cleaned and where they haven't. They clean until the battery runs low at which point they go back to their docking station to charge. But that's it, they're done cleaning at this point.This particular model, the R3500 vacuums in this random way. Does it matter? It depends - for me this model works perfectly, I have a nice open space for my kitchen, living and dining rooms, that's what I need cleaned on a regular basis. If you have a large house with many different rooms you'd like the robot to clean in one go (while you're not home for example) a higher end model is a better choice.If you have more open than closed spaces, this vacuum will work great. It really doesn't matter that it cleans in a random pattern, after a certain amount of time it will have cleaned the entire floor space.A few things I really liked about this Coredy model: *I have a few areas where the vacuum can drop, including stairs. The robot knows it's a drop and won't fall down. That said the owner's manual asks you to place a barrier to prevent it from falling, I'm assuming they're trying to cover all basis. They also sell magnetic strips that stop the robot wherever the strip is placed - I haven't tried them though, I don't really want those glued to my hardwood.*Floor saddles, I have 2 the robot needs to go over, I was afraid it wouldn't be able to but it does. I'm super happy because this way it'll clean a much larger area than I anticipated.*Rugs: admittedly we only have one medium sized area rug, and two small ones, the rest is hardwood. It does a good job with them though.*Remote control: easy to use, it has a number of different functions such as spot cleaning that I really like. You can also guide your robot wherever you want it to go by using the arrows on the remote. Kind of fun if you feel like you should be doing something instead of just watching a robot clean for you. There's no app for this model but you can set it to clean at a specific time everyday, before you get home from work for example.Cleaning the robot itself: the brushes easily come off for cleaning which is great because I seem to shed even more than my dog. My hair does get tangled in the brush but Coredy comes with a nice little tool that makes it really simple to clean. The dog hair gets picked up beautifully btw, I haven't seen my floor this clean since before we adopted our beagle mix 1 year ago. The dirt tray is easy to remove , empty and put back - my 6yr old daughter can do it. It also has a filter that is also easy to remove. You will get an extra filter and extra side brushes in the box.I can't speak for durability since I haven't had the robot long.Hope the review helps! I highly recommend this model.