Some issues with i337m here as well:
- Signal. As per above, when I first booted, cannot acquire signal. Forcing it onto LTE, it finally did, but 1 bar where under GE4.3 it had 2 or 3. I noted it now has a MG1 baseband.
- APN's. It installs all known APN's for Fido. My device did not pick the correct APN so it had no APN set initially.
- After first boot, I set up the Xposed Framework, rebooted, then setup Gravity and rebooted. At this point, the device refused to boot (stuck on splashing Google screen). Had to reinstall ROM (without wipe) to get it to boot.
- Got device all setup through TiBu restore. When I rebooted, device again failed to boot as per issue immediately above.
4.4 is super-smooth on the GS4 (no surprise)...but alas...Reverting to 4.3...not ready for i337m IMHO.