One of my suppliers started stocking them instead of the Smart boxes last year, so I decided to try them.
They are definitely a big improvement over the standard Smart boxes and I think they are even a little less expensive for the one, two and three gang sizes. I haven't used the OneBox though, so couldn't compare them to Arlington at the moment.
Either way, I'm sure a lot of box extensions and 1-1/2" 6/32 screws could be saved by using these boxes in walls that will have a tile backsplash installed.
I see that Allied even makes round slider ceiling boxes, which look interesting, but I haven't had the opportunity to try one of those yet. SliderBox