I just bought a TF700T second hand on craigs list. I wasn't aware of the performance issues before I got it. I only remembered the marketing material when it came out. At first, I had a lot of lag. I did a factory reset and the issue persisted. I then put clockwork on it and tried various roms, performing a full wipe between each. The issue was better, but I still got a lot of lag, especially with Chrome.
I gave up and figured I would put it back to the stock rom, or close enough to it, and resell it. I flashed the plain old stock JB rom found in the development section, the one that was only deodexed with no other mods, did a full wipe (including the system partition), flashed it, and let it sit for a little while. I've set it back up and have been using it a couple of hours a day with no issues.
I wanted to make a quick note just in case someone else buys a TF700 and comes looking for help. I figured this might at least help someone out there a little bit.