Sorry, but this 'great unknown' surrounding Terry Glenn scares me. If they can't get any sort of definitive read on it, they need to work on some kind of a backup plan. If he's on the roster Week 1, his contract is guaranteed whether he plays a single snap of football. After that, you're stuck and it's too late.
Crayton is a solid posession receiver, but he doesn't scare opposing defenses and the younger receivers all have the own 'warts'.
I would prefer that the Glenn situation be handled like the Pacman situation. The team gets insurance against not having the players' services and any contributions that they may make are treated as a bonus, not counted upon.