Guess depends on perspective. Materials , Anti Vib, Autotune, Manufacturing especially ability to cast complex shapes. Not certain building a 572 was even possible 30 years ago much less 50. From another...fun factor, that's a little different as that's a personal thing. Then there is the physics, efficiency turning fuel/air mix to rotational energy is certainly better than 50 years ago, not as much difference from 25 years ago. By the 1980's all the manufacturers knew how to make a two stroke run well. And THAT is where the arguments begin. I can buy any saw made in the western world. I have a couple 562's, a 572, will get a 592 as well. But nothing I have experienced is any more effective for what I do than the tweaked 372 class saws I build for myself. AND right now the 48mm's are the first choice for me when I reach into the almost 50 saw collection to get work done. And I have fun running my old Swedish iron, that's intangible, really impressed with the L77's. An addition of a versacut bar, elx chain, and an eight pin sprocket the chain speed in the cut is closing in with a modern 70cc saw. So everyone is right with their opinion, the pro with the latest and greatest, the vintage enthusiast with a strong L77, the guys building kits..those decision are right for them, what's wrong with that? Saws cut wood now just as they did 50 years ago, and folks love or hate them as they did then as well.So based on what I’ve read here not much has really changed as far as design in the past 50 years.