Well, if you're running any kind of home replacement (Pandahome, FreshFace, etc.), I'd recommend uninstalling and running it stock.
It's weird because I can't explain it, but I used to have some pretty significant lags (for example, it would take my contacts list about 28 seconds to load for awhile), but they pretty much all went away on their own; almost as if the phone just needed a break-in period. lol It still slows down a bit on occasion, depending on what app is closing, but overall it's usually pretty responsive.
But I can promise you that a home replacement, if you have one, will be a problem.
Founder of the Society for the Prevention of Apostrophe Abuse.