I own a brand new Brunswick table and a two year old Diamond.
My Diamond has 4.25" pockets and my Brunswick has 4.5" pockets.
My observation of ALL Brunswick tables: the pockets spit balls out. Heck, I can fire in a ball on my Diamond and I have more confidence that the ball will go down, even coming off the rail at medium speed.
Why is this? The Diamonds are made better. By that I mean that every table is hand produced in the Diamond factory. The rails are built for each table. If you damage a rail you have to send all the rails back to the factory so that they can make it a perfect fit. I was told this by a Diamond table mechanic who put my table together. Why do you think that Daimond guards its patent on its tables? They are indeed superior.
Brunswicks rails on the other are not made at the Brunswick factory - they are purchased from other sources, and not even the same sources all the time.
I love the Brunswick rails but I would rather have a Diamond ANY day. My Diamond has drop pockets and they are deep. The owner of Diamond likes one pocket and he made his tables with deep pockets for this reason.
One last thing. My Diamond is made of oak, and it is practically indestructable. There isn't a scratch on the rails.