I have a 90's CX bike. I've never felt held back by geometry or handling. In every aspect I'd describe it as excellent.
I did upgrade to modern gravel because the bike I wanted two years from now presented itself to me at a good price.
The whole stability thing is a bit overrated. Both bikes are incredible stable and sure footed (or I am).
I very much like the disc brakes. My hands aren't as strong as they used to be. Thru axles feel stiffer but I'm not sure they actually do anything.
It's a pound lighter and looks cool.