E175 is probably my favorite narrowbody plane, whether in Y or F, in terms of comfort. I like it better than 737's and A320's in any "normal" short-haul configuration found on a U.S. or European airline. The 2x2 config in Y is comfier at the shoulders. The 1x2 config in F is fantastic if you book the "A" seat. E+ will give you tolerable legroom.

As the prior two posters point out, E175 just "feels" mainline. I'm 6'3" as well and like being able to stand up. CR9 still feels like an RJ.

Neither aircraft has any safety issues that I'm aware of. They're proven and common in lots of airline fleets.