If you're going to tour with a load you'll want the triple. If you're not going to tour, or if you're going to do a supported tour where someone else carries your load, the double may be what you want.
I toured with an old 10-speed in the 70s. It worked, but I'm sure glad I had my 27-speed on my recent tour in the mountains.
When I ride my touring bike locally I almost never use the granny. I could do fine with a double if I never went touring.
I want to buy another bike for local rides, centuries, etc. It would be light and have a double. My wife wants new siding for the house and pavers for the back patio. Guess who's not getting a new bike this year?
