I was trying to make a grappling synthesist summoner today and I ran across two interesting things.
Improved Grapple has a dexterity requirement of 13. The grappled condition gives -4 to dexterity. The grappled condition would drop my character beneath the required dexterity for the feat improved grapple...
Also, I was discussing grappling with the party rogue and we noticed something. The grappled condition is replaced by the pinned condition, they don't stack. As such, the -4 dexterity is replaced with a -4 to ac. As such, it is actually EASIER for his rogue to escape a pin with escape artist than it is for him to escape a grapple.