I did the CP and it didn't effect my enjoyment in the least. Perhaps it's because I was fortunate enough to be places in a great area where my coworkers were all such fun, nice, lovable people and my managers were a blast. Most of the guests I came across were equally pleasant, and the ones that weren't I just didn't let them get to me. In fact, everytime a grouchy guest gave me a rough time, the other guests around were quick to jump in and make me laugh it off as soon as the person left. So never underestimate how much power YOU have while you're on vacation to give some of that magic back.
It also helped that I worked at MGM. Unlike the MK, the characters stay in character even backstage, I assume since the 'backstage' area would be so EASILY accessable by guests since all you have to do is walk around a wall, or at least peek around it (I'm sure most of you have heard about the headless characters in the Utilidors, LOL) Nearly everyday walking to and from work I'd pass various characters who would wave or greet me, just like I was a regular guest, haha.
To me, the time I spent backstage was just a chance to learn those little 'secrets' that everyone discusses with such interest here on the boards. People pay a decent amount of money for tours that I got to 'do' every day walking to and from work.