I don't have much more to add, but also look at the gears you normally ride on your current bike. Do you find yourself wanting "one more" lower gear when climbing a hill? How often do you use the big ring with the little rear gear?

As ehirsch said, everyone is different. If I rode her gears my knees would ache and I wouldn't want to get back on the bike; if she rode my travel bike, she'd probably find that her legs don't spin fast enough to keep it going at the speeds she needs.

When I picked out my gearing, I realized that I rarely used the big chain ring, let alone the 11. However, when doing long mountain climbs when the gradient skips up to 8%, I'd really like one more gear. So I put a 13-29 on the back and a 30-39-50 on the front. But, that's me and that's for the terrain I ride.

Look to see what you're currently riding and adjust (or not) based on that.