Never regretted a single one. I had a pair of 1984 Trek 620s in my size. I built the first one up for me, everything I like. Sure enough, someone wanted it more and I sold it. After all, I had an identical one in hand. So I fixed it up, perfectly to suit me, and guess what, off it went too.
I've sold every Italian bike I have ever owned, don't miss any of them. I've started donating more too.