I have to disagree i dont believe the Creation Kit for skyrim is any more "optimised" then the GECK for new vegas.
Skyrims engine is terrible and just as grossly unoptomized as all of Beths games.
Skyrims creation kit makes manipulating objects in the render window a little easier, but once you get used to the GECK it is just as easy.
I feel that lighting in Fallout 3/NV is superior to skyrim.
Yes there are differences between the Oblivion construction set/GECK/NV GECK/Creation kit.
But AFAIK there is nothing that can be done in one that cannot be done just as easily in another.
I have used them all over the years and currently have Fallout 3,NV,Skyrim and their construction sets all installed.
Just my opinions.
Feel free to prove me wrong.