I started with a triple on my first bike. Shimano 105...it just never seemed reliable and I had a lot of dropped chains, even when I was just pedaling along and not shifting the chain would plop off. Have had no such issues with my SRAM Rival double. Rode around Lake Tahoe a couple of weekends ago and never really wished that I had more gears. Lots of folks stopped midway up hills fixing chain issues, though. My bike performed flawlessly. I've put 6200 miles on my bike and only had 2 dropped chains.

I have a mountain bike on order...with that I am going for the triple, since that's what the 2013 version comes with. The 2012 was a double, but the fork on the 2013 looks like it will be an improvement over the 2012, so that played a role in my decision. I also rode a friend's bike with the same shifters and I like the Shimano shifters better than the SRAM--opposite of my experience on a road bike.