Everytime I've went into Cyrodil in the IC I get lag. The PTS they use can't handle a lot of people so it's always laggy. We'll have to wait and see on the live server next week how the lag really is.
Majority of people I know are not leaving because they can't fix exploits or they don't know how to code in general. People are leaving because you can't cast any abilities in PVP. I'd rather play a game with a few exploits here and there instead of a game where no abilities work!