Interesting...I also take the 1 train. This morning I noticed a little bit of signal at certain stations, but it was slow to appear...like, it would finally pop up just as the train was pulling back out of the station. Hm.
off to take it again now, will report back. another anecdotal example is i usually lose service in the stairwell of my apartment building and then it takes a block or two to resume on 12.0. i just walked out and it was full strength functional LTE