Train line through independence heights / garden oaks area

I'm looking at buying a house, and a lot of properties meeting my criteria are coming up in these neighborhoods. However, some of them are very close to a train line just to the north of W 34th street.

For those who live in this area, what can you tell me about this train line? I'm trying to figure out if this is no big deal, or a massive dealbreaker. How often is it used? Do the trains run during the day and night? Are there many crossings where the train horn is going off? Any info would be appreciated.