Yes, me too, still works as expected.

As for power saving I guess it is almost identical to locked keys except that both touchscreen and key controllers can be turned off completely (power key itself is wired to different chip due to obvious reason - it needs to turn device on from the real off state) so maybe just maybe there are more power savings. With just keys locked, keys still need to work and even touchscreen is not turned off completely as it was seen in previous firmware.

Otherwise it is almost same. Radio chips are still working, programs run.

I'm using it because it is simpler to lock and unlock the device as I have soft poweroff set to longer power key press.