We had an old saw GTG back in May, and we came up with the following definition of old saws as a target for that event: On the market before 1980 and no plastic gas tanks.
Using that definition, I cut about a third of my wood with vintage saws. Most of that is with my older Jonsereds, (49SP, 52E, 621, 70E), which get a fair amount of use. But those saws don't really feel that old to me, as they were a bit ahead of their time back then.
I also make it a point to take out my Homies and Macs and give them a workout, and like a couple of you guys I have a Pro-Mac 850 that I enjoy running. Have a few XL-12's and a nice XL-800 that I got from weimedog. Today, I'm taking a Lombard Comango with me that I've been wanting to try out.
I usually cut wood a pick-up load at a time, so the anti-vibe thing is never an issue with me. I always have a newer saw with me as a back up, but honestly, the old stuff is generally just as reliable as the new saws. One time it went the other way. Was cutting with a friend; I snapped a starter rope on the first pull and he hit a rock on his second cut. So we cut up the whole load with a Super-XL I brought along.