I've stayed at CBR twice and never had any big bus issues. There was ONE time when we had to wait 45 minutes for a MK bus to come. That was frustrating, but that was one time over the course of two weeks of vacations. ALL the other times everything was just great.
There are going to be long lines for buses EVERY TIME for EVERY (bus) RESORT after a big event such as Wishes, the fireworks at MK closing. If we stay until then, our strategy is to hang around in the aprk and wait for most of the people to leave. We get ice cream, or snacks, or just sit and rest/relax and do some people watching, etc.