I had an SS2. It shot pretty well and quite smoothly for about 500 rounds. Then the sear or some internal part wore and it wouldn't stay cocked. I sent it back to Compasseco for repairs. It took months and when it came back, I assumed they'd fixed it free under warranty. I found out later that they'd charged a credit card of mine that they had on file.
The SS2 was very crude in every way compared to an FWB and the cocking mechanism had sharp edges that hurt your hand after a shooting session. The sights were also crude and the back sight was canted. There were review articles on the web comparing the SS2 favorably with the FWB65, but they were untrue.
My advice: Spend the extra $$, get a nice used FWB, and don't look back.