I've not dealt with the SD series yet. I have an SW9VE... I've heard the SD trigger is a bit better out of the box but still not great. I put the Apex springs in mine- they helped, but the trigger pull is still pretty poor. Crisp and consistent, yes. It's also still very heavy and difficult to handle easily.
As for the sights, I don't know if anybody makes adjustable sights for the things... I put night sights on mine and I probably wouldn't recommend that somebody do that. It just didn't really do much for the gun.
It's a decent and reliable firearm, it's even reasonably accurate. But it is also inferior to the guns that don't cost all that much more.