My pretty new Rocky Mountain Metro 30, like all uprights, was giving my hands problems, so I got a cheap $15 North Road-style handlebar. Of course, changing the cables on my fancy hydraulic brakes cost about $70 all told. Grrr! I do love the power, modulation, endurance, and rain-proofness, though.
With the new riding position, wrists are much better, but I think it's starting to bug my lower back (an issue I was aware might come up). So now I'm looking at getting a Brooks sprung saddle to soak some of that up. And I've known from the start I'm going to want to get a smaller chainring, as I have a trailer for this puppy. It's meant to be really, seriously an all-rounder.
Ah, the never-ending cascade of upgrades . . .