Congrats on another good race. I would have guessed it was the result of the solid training you've been doing, if you had not given the shoes so much credit in several instances. Is the motion control aspect very noticable? I generally find it unnecessary and sometimes distracting, but would like to a least give them a go.
The shoes are like a new toy, can't stop playing with them! I tend to overpronate, and stability shoes (like Adrenaline and Kayano) help keep my ankles in alignment. I also replace the insoles with Superfeet, and the combination seems to keep me pain- and injury-free. When I was trying on racing shoes in the store, I could see that they were bad for overpronation, particularly the Nike Zoom. So it was nice to find the Fastwitch, which has a wedge under the instep to help keep it from collapsing. If you have good arches, you'd probably never notice it.
And yeah, I don't mean to downplay the training. It's the cake, and the shoes are just the icing.