I own both the P5 and P3, and to be honest I actually think that the C5 sounds better than both. Bass is thumping, but not overwhelming ( I mostly listen to house, trance, r&b/soul, rap). Highs, mids and lows are very good as well. I see a few people think they're somewhat uncomfortable due to the placement of the cable within the ear, but I haven't experienced any problems. They fit perfectly.
They barely leak any sound (if any), which is great because I take the bus or train to work.
And another thing, try not to smile when wearing them or they might lose the original fit. I'm always happy, so that might become a problem. If you're a sad/depressed person you shouldn't have a problem, and the C5 would be the ones to get.
Edited by Housebliss - 10/5/12 at 10:17am