The quick & dirty answer to this is that I'm too damn lazy to switch back and forth. I agree this would be the best method and give complete flexibility as to where & when the cups would be used.

I think if I go with the cups full time, I will have a little bit of that protective film applied. I generall dislike the stuff, but if the cups are thowing up everything the come into contact with, it's probably a good idea to do a little.

Mike