I know this is mostly personal preference, and I'm probably in the minority, but I really like 5" standard GC pockets the best.
When most tight tables were shimmed GC's instead of extended rails, I believe the "players" 9 ball tables were 4.75" and the one pocket tables were 4.5". That's about what they were when I measured them in a couple of popular Philly gambling rooms a decade and a half ago. My memory might be off...
I think Diamond's 4.5" standard pocket is good for one pocket. But for rotation games, I much prefer 4.75" or 5" pockets.
If the day ever came where I ordered a Diamond table for my home, I would request it with league cut pockets.
To each his own