It's tough to go back after seeing what modern technology has done to bring more dimension, detail and a more lifelike appearance to pretty much all the old favorites (figures at least). I still have a soft spot for some of the old stuff, particularly when put on display nicely somewhere, but can't see ever going back to the old O-ring Joes myself.
At this point, having gotten my first couple 6" figs, I doubt I'll ever return to 3-3/4" at all. And, while some still remain amazingly creative for their time, I've pretty much written off all the vehicles at this point. Even with the 25th vehicles, SW did such a better job with detailed, truer scale vehicles than Joe ever did or likely ever will.