I also have noticed the screen unlock lag. It only happens sometimes, which is weird. And I am *totally* shocked that this is a "known issue" with auto screen brightness, if that is indeed the issue. WTF did Verizon do with this update for the month they had it and didn't release it? I thought they were testing it?
I've noticed the screen rotation is smoother/quicker, as well as scrolling through the App Drawer. Nice little UI tweaks. Interestingly enough, I didn't notice the imporvements until rebooting the phone. Looks like the keyboard lag with long messages has been fixed as well.
As far as the audio mute issue, I have not had it happen since the update, but I haven't used the phone much since then either. I'm hearing lots of reports of this NOT fixing the issue, which is depressing because that's really the only thing I cared about. Verizon said it was going to be fixed, so I expect it to be fixed.
I had this long speech planned when calling Verizon if it happened to me, about how I've had this problem since January, I've tried three replacement devices, I want a premium phone, you've been very helpful, but may I speak to your supervisor? etc., etc., but then Spousal Unit reminded me I'm eligible for an early upgrade in October. Instead of going through the pains of begging Verizon to make it right by me, I'm just going to hang on until October and buy another phone. I've waited this long, and to be honest, I'm tired of worring about it. I'll just deal with it until October.
**edit** Forgot to mention, I did notice that 3G picks up a lot faster than it used to.