I've just upgraded my gen 1 Moto X to 5.1. I've managed to get the NFC "Skip" tabs working again to unlock the phone, but the overall behavior is worse than with the prior release.
Before 5.1, when I'd power the phone on I'd be immediately prompted for a password. Now, I have to do a "swipe up" gesture in order to get the password prompt to appear. That seems trivial but it kind-of ruins the Skip convenience. Before, I could hit the power button and wave the phone over the Skip magnetic tab on my watchband, and the phone was ready. Now I have to add in that (pointless) swipe gesture.
Is there any new configuration option to disable that, so that the password unlock UI is ready to accept a password (or the trusted Skip device) as soon as the phone is powered on?
edit — I've noticed that, swipe or no swipe, the Skip device won't unlock the phone at all if it's been some unknown amount of time (I think) since the last time I unlocked the phone.
edit more — more reading suggests that this is simply the way Android 5.1 (and the "Smart Lock" trust agent from Google) works. The NFC device, which formerly (thanks to some special Motorola software, maybe?) unlocked the phone directly, now is just treated as another "trusted device" by the trust agent and it works like any other such device — which is to say, not as well as the NFC device used to work. (It may be more secure, but it's certainly less convenient.)