I went in December and rode both. ME was a very crappy coaster, but I'm glad I did just to say I did it. CB is a much better ride, but getting to Circus Circus, walking back to the park, finding a ticket booth, waiting in line, and dodging kids may have not been worth it.
If you have the money, time, and willingness to get a few more credits, definitely go for it. If you don't get to it, it isn't going to ruin your trip at all.