i followed this thread, and LTE worked like a champ. Though i did not stay on a stock ROM, u personally used DirtyUnicorn rom, but still followed steps to edit the build.prop manuall, and flashed the radio .33. You must use the correct apn's. For US T-Mobile, there is a old epc.tmobile.com apn that does not get LTE reception even if you have a lte equipped device, i had to use the fast.t-mobile.com apn, im sure Telus has an updated apn as well.
BTW, i dont think it matter what android version your in, cause when i did this, i was on a stock 4.2.2 and it worked, and then i flashed over to the DU ROM, and made the same edits since i used a new rom, and it worked perfectly again. Make sure to press *#*#4636#*#* once all is set said and done and put the netowrk setting to LTE/GSM auto-prl. Not sure why the option for LTE/WCDMA/GSM is not available, maybe someone could help with that one???????