I suspect that the optical design is not much changed, but the mechanics look to have been re-worked. It also seems that the baffling is a little different. Old SN3 scopes I have seen had some problems with flare, while the FDN-17x has it under control. I still do not like the tunnelling and the scope is long, but the new turret is very nice to use, JVCR reticle is good, and FOV above 5x is very good.
My Tangent Theta is a better scope, but also a much more expensive one. I have a strong suspicion that the FDN-17x will end up on my list of recommendations shortly.
At a bit under $3k, it basically goes up against ATACR F1 4-16x50, Minox ZP5 3-15x50, and maybe a couple of other upcoming designs.
FDN-17x absolutely belongs in this group and can really hold its own.
I am sorta treating US Optics as a new company after all the changes and relocations, so I am taking my sweet time looking at the scope, but so far it has not skipped a beat.
ILya