I live in Maine, we don't even have "4g", let alone lte. I have not messed with my APN settings and data has been flawless for me. I get 3.5-4mb consistently at my house (3g) where I used t get anywhere from 500kb-2.5mb, with a rare spike of 3mb. I also have yet to try anything data wise on my phone that was "blocked" or didn't work.
AT&T | HTC One M8
Previously - LG G2, Nexus 5, HTC One, BB Z10, Note II, Nexus 4, Nokia Lumia 920, ATT GS3, Note N7000, Skyrocket, Infuse 4g, Inspire 4g , Atrix 4g, iPhone 4, iPhone 3gs, iPhone, HTC 8525, many dumb-phones.