I have heard good things about the Optimo frames. If you like your current frame, and if it fits good, is comfortable, and is in relatively good condition, then perhaps a new drivetrain is the way to go. You'll almost feel like you have a new bike when you see all that new flashy hardware on there.

But then again, you are putting in some miles and getting a great deal of enjoyment out of your bike. So if you buy new, it will be well worth the money you put into it. Think about the dividends your bike pays in better physical health, better mental health, etc etc. Plus you pay only once, and it's free to go ride it anytime you like, with the exceptions being tires and tubes and the like. The bike is a big part of your life, so it seems the expense is relatively small.