While you should bring your checkbook with you, especially if you are paying in dollars these days, the food and the view are well worth the experience.
My wife and I dined at La Pergola the night before they closed for their August vacation. We sat outside, like most guests, that evening and enjoyed what is probably one of Rome's best views.
We elected the tasting menu and without exception enjoyed all the courses and the paired wines. The service was excellent..well paced with no sense of urgency or delay. While we dine well seven more nights in Rome, this was the best.
A treat not to be missed in Rome! Grazie LaPergola!