Ok, so fixed the proximity sensor/keypad staying active during phone call issue. Did a Google search and found it's an issue with the Artixs also. Have to toggle Pocket Mode on/off. Pocket mode still doesn't work for squat, but at least my cheek doesn't keep trying to dial numbers during a call.
As for ambient light sensor, still buggy. Doesn't seem to react to light changes much. But tapping power button to cycle screen on/off seems to make it shift brightness.
Overall, having just come off half a decade+ with Blackberry, I'm more than thrilled with this phone. The ability to customize is off the hook. As much of Sprint's bloatware that can be removed has been. GingerBlur didn't do much for me, so now most of the phone is switched to Go stuff. (Go launcher ex, Go sms, Go contacts. Much, much happier with that.
Barring the small issue of auto brightness being slow/inop, I am loving this thing. Gotta get the hdmi dock. If for no other reason than it looks incredibly stupid having a usb cord sticking out of your phone at night while on the kickstand. But best note is that if you love to tinker with stuff and tweak it to hell, this phone rocks. Now about that unlocked bootloader.......