RE: What are the characteristics of a GREAT longbow?
YepBC. I agree with rybohunter--it can take years, not to mention lots of tries, to settle on a bow. Some folks seem to never settle on one.
Took me 4 years of searching, shooting, and driving different bowyers nuts to order my first custom. Even then, it wasn't just what I was looking for. One big problem for me was I didn't know just what I was looking for. Wish I had what I've spent over the years on bows!
I found mine by pure accident. I'd found the bowyer on a chat room I went to years ago (trad archery chat, just in case you are wondering). I'd never heard of him or the bows he made. Found a used one on e-bay, bought it really cheap. Soon after that I orderd one custom made for me, and it's been my #1 ever since.
I still try out different bows, and I've shot some really nice ones--but none I'd trade my #1 for. I've had folks ask to buy it, I just say "it's not for sale".
It's a very personal thing though--what's perfect for me might not fit the bill for you. Looking is part of the fun.
Chad