I personally tend to shy away from launch day devices. I like to let other people test out units, give real world feed back, then if i want one get it, Or i sometimes wait for its first sale. I did that with the HTC M9, i got mine at a HTC 25% off sale. I got my Note 4 after the 5 launched so i was able to get it cheaper as well.
Generally 2 months after a device is launched the hardware issues should be found and resolved after it hits mass market.
Im rocking a Note 4 N910T3 for TMO right now. The original was a N910T which for some odd reason got replaced with a T3 version.
Hardware wise i have no clue what the difference is but the T with 5.0.1 software seemed to have laggy issues, reception issues and battery issues. My T3 has 5.1.1 and i dont have any problems with it.