I like the 3445 Calatrava, but I do not "love" it. I think it is a beautiful reference that captures the spirit of the Calatrava. As a first piece in vintage Calatrava territory, I think its a nice choice. Much depends on how you want to view it. Patek made a lot of 3445, so you have a good choice on different metals and variations. Bottom line is that its a nice watch.
Having said that, my preference would be towards references like 2508, 2509, 570, 565, 3483. I own three of those and I bought them ahead of the 3445 because I find them more interesting. Everything is relative on a subjective level.
I am not sure I have made your decision any easier!!!