We did it in a day... a very LONG day. Scheduled the shuttle for 8am, actually left at 8:30, made it to the trailhead by about 10am, unload/hike down/gearup and put on around 11:30. Pulled into the Pleasure Park around 6pm. Definitely worth it to pay $75 for the shuttle (remember to tip the drivers, they really appreciate it). Here is a link to a good description of the rapids: http://www.co.blm.gov/ggnca/gorge.htm
It's a bit hyped up, but very detailed. Be prepared for the long paddle out. It seemed like it lasted forever. If you are camping at the PP, bring the bug spray as the misquitos are horrible! The store/bar is limited, closes early and they only have cheap macro brews, so get what you need when you drive through Delta. And, they only take cash for camping.
Let me know if you want more details.