At least unfair to try to compare a paid for, industry veteran, which can allocate far more money to his creations and learning techniques and years of experience to a hobbyist.
That said, SD is one of the best creators in Fallout art community and his works are always excellent. He's better than a lot of commercial work I've seen.
His current works are excellent as usual, and much more Fallouty than Mr. Mullins' that some tried to compare him to(and like I said, there can be no comparison, far more because as SD himself stated it's 3d vs 2d, cannot be really compared).
For the record I consider SD's best work to date to be the Redviewer scene. That could easily be in the Fallout original.
As for Mullins, his artwork for Bethesda was pretty good for any generic game...WITHOUT Fallout in the title. He's way off when Fallout is put on play. Even if they didn't brief him or helped him, there is a huge Fallout community and it wouldn't be that hard I like to believe to do his homework(and that's what makes or breaks you as a professional).
BUT, we're talking about FO3 here, it's not like it is the last of the problems with this game. I'd be extremely happy if the problem stayed there, but we all know now there are far more concerning problems with it.
SD, as a fan has an extra advantage, that he knows what Fallout is about, so every way you look at it, his work apart from being a joy to look at screams Fallout as it's supposed to be.(which is what gives validity to Brother None's complaints on game makers not knowing Fallout or being fans of fallout, though it goes a bit overboard in my opinion when it extends to game testers, whose work isn't to give the Fallout tone, but to see if there are bugs and such, unlike game makers who should have a good grasp of what they're fiddling with)
And I'll agree with brother None, I too anticipated the concept art on Bethesda's site, but with a different motive: NOT to admire it, but to see if they finally managed to get a better Fallout grasp than the previous shot, which they failed to do every single time. Infact, the only thing that I really liked of Bethesda's work so far was the trailer(excluding the Atrocity armor bits), which was as Fallouty as you can go. I'm afraid it will be the only thing however, but who knows, miracles happen.
And since this is a Glowing Grounds thread which I derailed, I have to say, excellent work so far, my personal faves are Trading post and Control room, which are on par with the Redviewer scene IMO.