At the National events this year, we (BCA, VNEA) used the 7' Diamond Smart Tables. Many didn't realize it, but 100 of those tables for the amateur event had the 4 1/2" pockets. The rest were 4 9/16". My local pool hall has 9' Brunswick Gold Crowns with nearly 4 3/4" pockets. Do the math.
All of the tables at the Nationals had the faster worsted cloth. My local pool hall with the 9' Brunswick tables do not. That is, pocket size and cloth do not a bar table make.
A bar box is the size. Many table manufacturers make whatever they want for pockets. That's why we need standardization. Some pockets are just too big. But, that's true for all tables, regardless of the size. All Dynamo and Valley bar boxes, the side pockets are much smaller than a 9' table. I'll guess up to a full inch smaller. Do the math.
I think that those who get to play and watch at the Nationals get to see what the difference is between excellent bar table pool vs. excellent pool player playing on bar table. Too many people (who don't go to these events) judge their game on a bar pool based on shotmaking and based on playing the local scene. If that's your take, you need an enlightening.
As Jude said, the top bar box players put mucho effort in getting perfect cueball control and precision. The table is entirely too cluttered to get the sloppy patterns afforded by a larger table.
On this board, many people haven't given the bar box skill the respect it deserves... until they go to a National amateur event or a bar table event that features the top bar box players. And they come on here and report their change of view.
Fred