I started riding an aluminum Trek 1200 about 13 years ago. It served me well (read: made me want a nicer bike!). I had a bike custom built 8 years ago & the difference is incredible. For one thing, I went to a steel frame which is much more comfortable. It handles well & fits like a comfortable shoe.

If you're just doing one race - I don't think I'd sink $5K into it. But if you're planning on doing serious riding, I'd recommend an upgrade. If nothing else, the components are much nicer on the newer bikes.