A few years back when all I rode was my Rivendell, I wanted to try a carbon bike since I had never ridden one and of course they were all the rage. I test drove a Specialized Roubaix and I just couldn't find anything wrong with it. The bike rode like a dream, I just couldn't find fault with the bike at all. As nice as it was I just couldn't see myself riding it. I just didn't need it.
My point, try test riding a bike first and it may be everything that you think you are missing or it may be something you really don't need. I am not the first in this three page spread to suggest this. It is always easy to spend someone else's money, so it would be easy for me to say, buy a new bike but is it the best advice for you?
Good luck with this decision. It would be interesting to hear your thought process now that this thread is almost two months old and you have had time to evaluate the advice you have been given.