Back in 2005, I bought a Trek 1200. It was my first bike since I think middle school. I'm going to be 40 next month. Here's the model I'm talking about:

http://www.bikepedia.com/QuickBike/B...1200&Type=bike

Now, I rode it for the first year using some plastic platform pedals, and never took to it. It hung in the garage for several years. This past spring, I pulled it out again and over the summer started riding with greater regularity because I found a couple of my friends were getting into cycling. Over the summer I switched to Speedplay zeros which I love. This winter I bought a trainer and have been riding it daily to get into better shape for the spring. In 2011 my goal is to do my first century.

Because I started riding more, I started looking at more bikes, and started riding some at some local shops. This was a mistake! Well, I did determine one thing, and that is although my Trek is a 56, I'm more comfortable on the 58s I'm riding at the shops. In 2005 I went with the 56 because the standover height was too close on the 58 for comfort. Well, with the sloping top tube designs I was riding in the shop, that isn't an issue anymore. I did go out and swap my stem to a 120 mm (the stock one was 90), and this has helped a lot. I just needed a little more reach.

Now, I'd LOVE to go and purchase the Scott CR1 Pro I rode back in the fall, but let's face it. I don't need (and my skills don't really deserve) a $3K bike. But the things I liked about it most over my Trek were:

smoother shifting (and I really like the greater cable pull on Ultegra 6700 - makes me feel like I can shift without really pushing the lever WAY over)
lighter bike
better braking
compact double (my Trek is a triple, and in Indiana I've never needed the "granny gear")

Is it worth upgrading my bike, or should I hold off? I was thinking about buying a full 105 5700 groupset for about $600, which would help a lot with the items above, but is it worth putting another $600 into this bike?

I'd really appreciate any input or thoughts.