Replaced the battery, now all of G2x's issues are gone!
I'm using the old G2x (with CM7.2) as I sent my HTC One in for a repair, and I was reminded how laggy, buggy, and crashy it was. THEN, I replaced the battery with a 3500mAh extended version online for $12, and all the problems seem to be gone!
Before, applications lagged, the keyboard lagged, the dialpad lagged, I couldn't automatically sync my phone's time, etc. Now, virtually all of the lag is eliminated, it automatically synced the time without a problem, and it feels like a new phone. Load times are still long for intensive apps, but the phone is actually fun to use again.
Now I'm wondering if the battery was to blame the entire time. Has anyone else had an experience like this? I'm just amazed at the complete 180 change the battery has caused.