Preaching to the QIRE

I have been away from home of late and don't have my copy of Clark's Recovering the Reformed Confession handy to cite directly, but there is a topic he addresses that I'd like to put forth for discussion. In one of his chapters he addresses the issue he calls the QIRE, or, the quest for illegitimate religious experience. One of this problem's main culprits, Clark argues, is the phenomenon of revival.

While an in-depth post on revival will probably have to wait until Monday, I am curious to hear your thoughts on the matter. Are revivals legitimate? If so, which ones, and by what criteria should we determine a revival's legitimacy? How much tension, if any, is there between confessional Reformed piety and practice on the one hand, and what many Banner of Truth authors call "experimental Calvinism" on the other?