I took over for another GM. It was before any actual game play, but after the players had created characters. They decided to go with Chest Deep (8 starting refresh) so that all the templates were available. I didn't see any reason to make them re-do their characters, so that's where we started from. We had 6 players, and I intentionally designed the NPCs to be in a range around their levels.
Looking at in in retrospect, it might have been easier if we had started with a lower refresh overall. It does make playing (and GMing) simpler in that you have fewer powers and such to deal with on a regular basis. However, my players really enjoyed having the full spectrum of templates, and we used the first couple adventures to let them "feel out" their characters and make tweaks where needed. So it's turned out to be fun regardless, which is the primary goal in my opinion.