I have all sorts of bikes. Last December my brother ran across a Fuji Newest frame in my size and gave it to me for Christmas. I had it put together with barends, shimano derailleurs, a set of old Ultegra calipers that I'd had laying around, a set of Nasbar normal brake levers and a Look HSC-1 fork that I'd picked up from the racing team throw away box down at Sea Otter the previous year. I had been given some Mavic Helium wheels because the spokes were all loose and the wheels were way out of alignment but I had my local shop owner who is a really good wheelman, set them up with proper tension and they're perfectly straight and true.
Not only is this one of the best riding bikes I've ever owned, it's also one of the lightest.
There's nothing wrong with aluminum frames if the geometry is right for you.