I recently bought Skyrim Legendary edition on Steam from the late Fall Sale (all praise Gabe N. our lord and savior of the PC Master Race). and i saw the tek about SMAA, sooo i found a mod that made it in and oh my god the game runs even faster, i was able to dump it into a higher settings with it on.
note i'm using a Geforce GT 630 2GB version with GDDR5 VRM (i dont know why it has GDDR5 when it cant but someone made it, and it was on sale for 50 bucks last year, good start at least) and plan to buy a GTX 970 within the coming weeks.
FPS Before: 80 FPS with no action or cave and hits around 67 FPS when pushed and maybe to 45 at some points like dragons and stuff / Settings: Medium
FPS now: 90+ FPS with no dips 100% never below 60 FPS no matter what / Settings High with SMAA at 2x
From what I read, SMAA is like FXAA, but smarter. I must look into it, considering I'm running my games at 1440p or higher resolution on my GTX 760. Downscaled to my 1080p monitor, aliasing is still a bit of an issue, and at that resolution, MSAA is typically not an option as it's way too taxing. I've found that FXAA is good, but if SMAA is also very cheap in terms of performance penalty, I may just start using that instead.
SMAA is amazing. It was my go to back when I gamed on my Lenovo y570 laptop. It let that little gt555m punch out of its weight class time and time again, giving me a great introduction to PC gaming. Nowadays I don't really use it as much, since my GTX 770 stomps everything at 1080p, but I am considering a 1440p monitor, and if I do that, I will be laying on the SMAA sauce again for its tasty graphical goodness.
Games that use differed rendering engine will appear to have LSD like graphical artifact if you try to interject SMAA. That's what's really annoying, but perhaps with VSR on my AMD I can enjoy Dishonored in all it's glory now!