We got the J9+ to replace our J7 we were using on our main floor of our home. We of course will keep the J7 and move it to our basement because why not have 2 roomba's when they work so great. I already knew how the mapping worked so it was simple enough to get the new roomba onto my app and start the process. I was pleasantly surprised when it only took about half the time as my other one did! I noticed the suction on the J9 is a lot better and it holds a charge quite a bit longer but I was most excited about the emptying station as my J7 did not have one. When I say that thing is convenient, OMG I mean it! I love that I don't have to empty something constantly. Overall I find this roomba to be the best one I've gotten so far and I can't wait to see what else they come up with in the years to come!!