For us, Trevi Fountain was empty and under restoration. Michelangelo's Pietà was behind bulletproof glass. Carravaggio's Saint Matthew was illuminated by coin-operated spotlights. All checks off my extensive art bucketlist, but not quite what I expected. Was I disappointed?
What I realized is that you can plan to see all you want in Rome, and probably fit in much more than you ever thought was possible, and still, it will never be enough. You want to see just one more thing, or you want to see it again, and you always notice something new. Rome really is a never-ending choose your own adventure.