@eguess: UPDATE: after not being able to revert back to 3.1.3, I reinstalled 4. It's working better now! It's not great, but it's obviously better. The Sounddock issue is fixed, too.
So, what can you do if you don't happen to have a pre-OS4 backup? Apparently, I don't have one. Am I just stuck with this slow piece of trash now until I buy a new iPhone 4?
On a side note, I'm super happy for you 3G users who aren't having any problems, but my phone is JACKED! It lags, freezes, and straight up doesn't work from time to time.
It may be a coincidence, but I'm also having issues with connecting it to my car and Bose Sounddock. It will charge but not play. I'm just saying that may be due to OS 4 only because it worked before but doesn't now.