Hmmm. I would never go that far, but m42 stuff will always be part of my kit. I also have the Pentax 1.4, and I shot a kids party this weekend, and I had the best shots with that lens over the 2 other "L" lenses I brought as well. Now that was basically due to FL, but going through them, that lens has a serious look and IQ.....if it had AF and a red ring at $1000 people would be singing about how awesome it was for a bargain price.
I did something similar though and have completely gone away from zooms, and I have seen the value of really fast glass and the flexibility comes with it, so no more 2.8 stuff for me either under 200mm. for me, I like the feel of pictures a lens renders, not just "sharp" (which i would trade all day for feel) and good primes for the most part do that, and also for the most part old schools hit that nail on the head.
There are still some lenses you won't replace with the old stuff. My favorite current lens is the 24, and I don't think there is an optical equivilant for that. But 50, 85, 100 etc. great FLs for old school quality. I wouldn't go all old school, but I would never blame anyone Who did and totally get why. I just finished an awesome Bob marley documentary, and all the photos are from lenses like these and film obviously, and the pictures really struck me as they just had more soul than a lot of what I see today, regardless of noise and sharpness.