Personally (and using the sorter right now) I'm checking my lists after they're made, and making adjustments which don't look right. But on the whole it seems pretty good. The main issue is, what it's essentially doing is asking you to place a card among the ones you've already sorted, and if you place one wrong early and it ends up about 1/2, 1/4 or 3/4s of the way through your list, it can really screw things up, as those are basically the key points where comparisons are going to hit. For example I think I put one of my $3's slightly higher than I think it deserved (Market Square I think), and ended up putting more stuff above it, but it ended up with a bunch of slightly better cards below Market Square, and a bunch of slightly worse cards above it, which I fixed by hand.