every company drops calls, every company has spotty coverage, etc. t-mobile's data network does suck though, they just don't have the technology or footprint.
I am know you are right on the calls and coverage.
I am believe you on the data network note.
Just speaking from my personal experience. Where I travel, there are 2 or 3 consistent spots where calls are dropped(all low spots in the middle of rural areas). However, I get practically zero drops outside of those areas. Where, with Sprint, I was dropping calls in the middle of Hyde Park, Midtown, and down town sometimes and not others. It was completely random and inconsistent. I just don't experience that with T-Mobile.
I haven't had a smart phone on the sprint network in 3 yrs, though. So, my experience with their data speed is not enough to fairly compare.