Great springer scope. Ive got one on an HW50s out in the gun room right now, and it's been on there for a couple years. They can survive a springer, no problem.
In fact, I've got three of them, and all the 20x with the mil quad reticle.
As you've seen from the responses, most people don't love the 20x but I think they're great for my uses. I had one on my primary field target PCP for a while and was winning matches with it towards the end, before I upgraded. I really like them for pesting and paper. Thick enough, but not too thick reticle. Hold over or click the turrets, both work great.
I think most of my love for the SWFA SS comes down to familiarity, as I've spent a lot of time using them. Not overly complicated or gadgety, just a good, solid scope. Less is more with these scopes.
Cons: eye relief pickiness and a little bit of a murky image
Are the two big downsides.
Are they my favorite scope? Nope. BUT, are they my favorite $250-300 scope? YES! They've allowed me to keep multiple guns scoped with trustable glass, without needing to swap scopes around all the time.