Just to revive this thread a bit, I've used a magic rack for years and recently purchased both an accu-rack set and the turtle rack. I would rank them:
1) Turtle Rack
2) Magic Rack
The Turtle rack is pretty amazing. The balls fit perfectly tight first time on, and for any game. It's sturdy enough that it doesn't move/bunch up. And it's easy enough to remove even with balls inside its perimeter. Bonus points that I only need one rack for all games.
With the Magic rack I still had to check carefully to make sure there were no gaps, and the 8-ball rack especially was flimsy and move-y enough that it a bit of a pain. It still worked great, overall, but there was more to deal with.
I don't like the Accu-rack much at all. It's very flimsy and pretty easily moves around the table when racking so I have to be super-careful. It's got ads on it (??) and writing all around, including written directions to "load 8 then push." And I found when I do put the balls in there are gaps so I do have to push them together, just like a classic wooden rack. It's just too much for me--too much having to be careful, too much fiddling, too much visuals. Maybe I'm just not appreciating what it does do well, but my concern is racking correctly and quickly with minimal fuss. It will only do in a pinch. I did really like the sturdy plastic sleeve it came in, and will probably use that to tote my racks around.