Components interest me a lot less than frames, I always bought stuff purely for the frame and fork, and if the fork wasn't rigid then I'd just buy the frame.
I primarily run newer components as they're often better and cheaper.
The only vintage components I'll spend my cash on these days are cranksets and the occasional wheelset, as I've found that there's some real quality to be found. And also I still like square taper, and modern offerings aren't quite as interesting as retro ones. That said, BETD still offers middleburn cranks, so I'd probably pick those any day of the week over a retro crankset.
There's some nice retro groupsets but they're not going to outperform a basic 105 or deore of today.