Old steel bikes have made a comeback in the UK with the onset of the fixed-gear cycling scene, some are intentionally left scratched/rusty to stop them from being stolen, while others are lovingly restored. Steel track frames to me look especially mega awesome.
I have a Ciocc 1978 frame with 1980 Super Record, it rides great but as I am not an expert on modern road bikes I've no idea how it compares. Carbon era riders may think it slow/heavy probably...
The old cycling races weren't always done on perfectly nice roads, so a very stiff very steep angles frame may beat you up more than it's worth as it will be more jittery over bumpy roads/sore.
Luis Ocana's bike weighed only 8.6 KG! (It was full of holes he went Drillium to the max)