It's all what you're used to. I rode Reynolds 531 and Columbus SL road and track bikes from the mid-'60s to the early '90s and loved them all. I've since gradually replaced all of my steel bikes with aluminum bikes; love those even more.

I absolutely agree with the posters who said that wheels make the biggest difference. The only bike I had a little trouble getting accustomed to recently is my 16-lb aluminum bike with scary light American Classic wheels. It was twitchy on the downhills until I became more acclimated to the handling. Thought it was the frame geometry, but then I remembered that my first set of ultralight wheels (Hi-E, for the old timers) felt the same. Those Hi-E wheels instantly turned my Bianchi Specialissima Supercorsa into a skittish colt.