We've been on CS for about 90 days and we love it.
Several key things for a practice considering CS to know:
1) you will need a designated interal team (2 or 3) to do your set up. (1 person can't do it)
2) get a good IT guy and keep him/her in the loop
3) plan, plan, plan ... set dates for "get ready" deliverables and know what everyone's going to do on day 1.
4) prepare your team ... train and expose them to little chunks of the new application weekly. Each person should start by learning just what they need to know to do their own job. then branch out and learn about other functionality as they become more comfortable. Don't try to know it all day 1.
We're getting ready to upgrade to 8.3 within the next couple of weeks.