We co-sleep and I think it's great! I don't think Tamsin's waking more often because I'm close, but even if she was I think I'd still get a better night's sleep co-sleeping and feeding more often, than I would if I had to get up (less times) to feed her.

ETA: Fletch, to answer your questions - I only sleep with her at night, although she sleeps better during the day if she's on my lap (or DH's); she goes into our bed on her own if I'm not ready for bed and I sneak in later, but we've moved the bed off the frame and onto the floor so if she rolls off the mattress (and she doesn't normally even wriggle) she won't get hurt.