I strongly disagree with waiting to visit. If I had not visited, I would have never known where I wanted to go. I fell in absolute love with Yale on my visit, and my visit to Penn made me despise the place (no offence, it just wasnt right for me)
However, prior to my visits, my opinion was the complete opposite. Penn was my dream school, I wanted Penn more than Harvard, Yale, anything really. Wharton was my passion and I wanted in more than anything. But, (insert visit here), I found out I really didnt like the place and if I had applied/accepted Penn prior to visiting I really dont think I would have enjoyed my next four years as an undergrad.