In reality, as long as you got your GNex from Google, I'm not sure it does matter. They do roll out updates in waves though it seems. That's how it was with my G1, my N1 and now the GNex it looks like. Google will hit you when they hit you. I was floored and spoiled with my TF101 though. If there is an update out there for the Transformer and you hit check for updates.... it actually finds it!
I thought maybe it was some new leaf being turned over by Google but I guess that's just an Asus thing.