A few comments:
1. Diamond has the Pro/Am, the Professional, and the Paragon, in the commercial space. They all play exactly the same, as the under-the-hood stuff is the same on all 3. 99% of the Diamonds you will see are the Pro/Am. Make sure you see pictures of both the Pro/Am and the Professional, because aesthetically, they are completely different.
2. The Professional can be ordered with rounded corners, or 45 deg corners. Both give a different look.
3. The Professional can be ordered with 2 different leg types. Both give a different look.
4. All of the tables can be ordered with or without the big Diamond logo engraved into the end.
5. The main difference in play between a GC and a Diamond, is how the balls react off of the rails, and how the pockets accept the ball. You will have to find a Diamond for yourself to see if you like these two characteristics more/less than a GC.
6. The shelf on a Diamond is much deeper than a GC. So, a 4.5" pocket on a Diamond plays much tougher than a 4.5" pocket on a GC.
7. Diamond tables can all be ordered in 3 different pocket sizes. "Pro-Cut" is their standard pocket at 4.5". This is what all of the tournaments are played on. "League Cut" is bigger at about 5.0" and is a special order. They also have a tighter cut, I forget the exact name, usually ordered by one pocket players. Its about 4 3/8" if memory serves me.
8. GC tables from the factory measure 5.0" at the corner pockets. If you were in a "player's" room in the 80s, the owner may have had shims added to some or all of the tables. A "double shim" GC, common for 9 ball gambling, was about 4.75". A "triple shim" GC, common for 1 pocket gambling, was about 4.5".
Good luck and have fun.
