In reply to andrewmcleod:
Nah, most routes you don't need huge gear above camelot 4.5. It's more like duplicates (or triplicates?!) of camalot sizes in the 0.5 to 2 range, as has already been said. My 4 aliens didn't see a lot of use. What you've got, together with your friend's cams, sounds ok; you'll surely want your friends ones too so hopefully they're trustworthy and not 100 years old
There are exceptions: I recall one route where I seconded the crux pitch, and the the rack of the old-timer that led it was mainly the biggest hexes I've ever seen, like 8-10 inches across. I was quite bemused by them standing at the first belay, after I led an easy entry pitch, but honestly they fitted like a charm and made complete sense, at a fraction of the cost (and weight) of 4 or 5 cams of that size. It might be Fireball, I think's its an HVS, but feels like virtually E1. He did it every year, so pissed up it, while I huffed and puffed to second it clean, bruising my ego in the process given it was "only" hvs.