I think pocket facing angles can be a big factor.
I play my league on 9' Diamond red labels. The pockets are pretty generous width wise but they play super tough, balls rattle like crazy on these tables. The pocket facing angle even looks a little weird on them, though I haven't figured out what it is exactly.
I also play on some 7' Diamond blue labels with noticeably tighter pockets, at least 1/4" tighter if not more I'd say. But in comparison they are so much more accepting it's crazy, shots I think I surely missed on this table drop.
Could be some difference in shelf depth too I'm sure, not sure how to measure that.