If you are in SF (based on your SF craigslist ads), rent a modern bike and take it out for an all day ride. My bike is also getting old, a 2005 Kuota Kredo with Campy Chorus 10, not quite as old as yours but still old and I rented a Specialized Roubaix with 105 11sp on it when I was in SF in November. I took it into Marin up some hills there and some hills in the city and did 45 miles total. It was an eye opening experience. The components work better, the road feel is much smoother, the climbing was easier with the much lower gearing, but you don't give up the high gearing either. It had a suspension stem and disc brakes and wider tires. It all added up to a much nicer experience. When I got back and realized I'd done 45 miles I was amazed as I didn't feel beat up at all, and this is with the hills that I'm not used to here in NYC and the SF fog that I wasn't prepared for so I was cold off and on. I have since upgraded my bike with a Shockstop stem, and with wider GP5000 tires. These partially took care of the road feel but not completely.
The flip side of this is that I just fixed up an even older Cannondale with new levers and calipers (the old ones barely stopped) and I took that for a spin yesterday and was surprised at how well that bike handled. It was from the late 80s so really getting old with 6sp. It was for my daughter who has fallen in love with this bike for some reason. It was sitting in my basement and my wife had bought it new and then never used it so it didn't cost anything other than the brake upgrade. I put an almost new GP4000 on the front and I have another GP5000 for the rear that I haven't gotten to yet. The GP5000 is a 23 that I replaced with a 25 and a 28.
Ride what you have with some modest upgrades, but consider what you'd get in something new too and save your pennies. I considered looking at new but at my age anything new would easily outlast my riding years. I'd be 80 by the time I'm in the same position again with an older bike. Even in 5 years at 70 I doubt I'll be able to push 800 watts like I can still do now. If I had a new bike I'd be dead at 65 because my wife would kill me if I got yet another bike.
Last edited by zacster; 07-11-20 at 08:40 PM.