I ran this robot about ten times over two weeks before returning.  The first few goes went flawlessly.  It went back and forth, mapping and cleaning without once getting stuck.  It didn't seem to pick up as much as what it was meant to replace (and a subsequent use of my old robot showed it hadn't).  The last five goes were too troubling to risk keeping (even though I bought the lifetime warranty).  Two times it got stuck in one room and just kept vacuuming that one room (once my dining room, once a bedroom).  It started getting stuck more and more.  Cleaning sensors didn't help.  The self-empty base worked well.  I'd hoped that this would be my robot vacuum for the next six years, much like my Shark upright has done so well over the past six years.  Instead it was worse than my old Shark robot, which became far from ideal after the first two months.  I know it costs half as much as the targeted competitor.  I doubt it comes close to doing half as well.