I have gone through 2 children using the "baby swap". Disney is great with them. They do change how the individual rides do the baby swaps sometimes.
For instance, TOT used to have you take the child through the pre-show and when you got to the ride they would have someone take you down an elevator to wait. Then when your party gets done, you switch and you get elevatored back up to the next departing elevator. The last time we were there, we had to wait at the exit with the child till the party got done. I like going through the wait with my family better. Same thing has happened with Space Mountain. They used to let us walk through together and then walk to the exit. Then the person who waited walks back and gets on the next ride. Last time we had to wait outside with a "pass" till the party exited the ride. It takes longer this way.
Some rides are easier to do with a baby swap than others. My daughter loves that she gets to ride things twice. My son is now 44 inches though, and she is not getting to do the baby swaps as much!
Melanie