I didn't realize I had a double on my new bike until I hit the first steep'ish hill and couldn't get the bike to shift another gear. Oops. Turns out, I've been very happy with my double even on hills. I did change out the cassette for a mtb'ish one which gave me a couple of easier gears for the bigger hills. I now live in Wales with monster hills and this set-up works just fine for me and I'm not a strong rider. I don't think I would now switch to a tripple if I was looking for a new bike, but I'm not certain until I've tried both options I guess.