Pairs is quite hard, you don’t really get much of a chance to recover between stints even if you’re running doubles, which most people do, but that said, I’m quite a normal sort of rider and we managed pairs there a couple of years back.
Also, you won’t see your riding partner for longer than 30 seconds or so at a time during the race itself, so you don’t get quite the same sort of warm, fuzzy, team love you get with, erm, teams. Mind you, that can be a bonus depending on who you’re riding with.
If it’s your first 24-hour race, a team is a slightly gentler introduction. But got for it, what’s the worst that can happen, other than iDave following you for 20 minutes ogling your ‘team strip’ 🙂