I've used all 3 over the 30+ years of this hobby and I still prefer canister/HOB combo over anything else to be honest. I've tried the sump a few times and really just don't like them at all and I do see the appeal they have and I do know they work, however I just prefer canister/HOB. My ac110 takes 10 minutes to clean, the XP3 is a breeze to clean, the CFS 14i is just cleaning out sponges and my 2262 doesn't need cleaning near as often as the other because I just use it for bio. I like my 2262 so much that i'm going to get another here very soon and I believe the eheim is worth the increased price tag it carries. If after all these years I was to say what is the best, they all do their jobs and will last awhile (for the most part) if taken care of properly and you do the routine maintenance on them they require.