I assume you're talking about the "touring double" setup I rigged up on my bike. You can read the details of my trip here But the bottom line was that a 34-34 granny gear was low enough for 85% of my trip. But there was a significant amount of unavoidable (or didn't want to avoid) hills where I sorely would of liked a few lower gears. I ended up pushing my bike up quite a few hills.

If I do it again (I have a trip from Montreal to NYC for next spring) I may go the extra mile and put a proper triple on, but whether or not I actually do would depend on the topology of my planned trip. Anything with only occasional hill work and/or low grades I wouldn't bother, however any trips across Pennsylvania would probably mandate a "triple-ectomy"

On the point of how did the basic mechanics hold up over ~1000 miles - the grade was a B-. A bit clunky on the gear changes and I got a serious chain jam (possibly not related to the work I did - but I doubt it) that entailed a visit to Bike shop for fixing mainly because of my lack of 'how to fix your front derailleur' training.