I have an SA 2 from that era, and a modern PSA. The biggest difference is that sometime, I think in the early 2000’s, they switched to CNC machines for making bows. This means that if I want new limbs for my modern PSA, I can just order them and they will fit. If I wanted new limbs for my old SA, I would have to send it in so they could shape the new limbs to fit. I'm sure there are other differences beneath the surface as new materials or adhesives become available, but you would have to ask them about that. I believe my old SA is the same quality as a new PSA.