AM parts have allowed us to bring lots of good saws back to life that would have been unaffordable with OEM parts. For me, I mostly work on 044/440, 046/460 and 066/660 saws. Meteor pistons work as good as OEM and are often half the price, AM tank holders and recoils are far less than half of OEM, you just need to know what OEM parts to use with them and how to make them reliable. And, all the plastic covers work and are cheap (with some modifications here and there). I have also had good results with AM coils, but mixed results with AM carbs. I rebuild the OEM carbs whenever possible, and even bought some new OEM when I find an OK price for my higer "performance" builds.
OEM controls work better on AM tank holders, and OEM pull ropes work better on AM recoils, plus I always check them out an spray them with some silicon.
I acquired many of my saws by fixing other saws. You get 9 broken saws, fix 5 and give them back to original owner who lets you keep the rest. Fix and sell 3 to more than cover the cost of all the parts, fix and keep the old 066 for yourself!!!