I figure if you already have STI shifters and as long as the stem isn't creaking or flexing [too badly], just should just ride the thing and enjoy the compliments from people who remember when it was contemporary.

If you don't have a modern bike, this is not a bad platform to upgrade, but carbon is so cheap these days, you'd probably be better off financially getting a modern carbon bike (madone) at the complete bike package deal price instead of trying to modernize this one, one part at a time, paying retail for every single part.

Plus: 2 bikes > 1 bike[s]