Who said NXT shampoo is up to "Autopian standards" (whatever that is...)? I haven't even seen the stuff in stores let alone used it (not that my views are more valid than anyone else's). Nor have I read much from anyone anywhere about this product.
Jeez, let's not simply rubber stamp every new product Meguiar's or whoever introduces with the Autopia Seal Of Approval. I don't know there's many people using the Sonax shampoo either.
I'm not sure where your comparison came from. One shampoo that's not available at retail nationwide and another with *very* limited distribution.
There have been a lot of posts and a few polls that discuss favorite shampoos. Ya might want to have a look at those before assuming which product is a community favorite.
Making a nice sudsy shampoo is not rocket science. There are quite a few good ones out there. Most people base their decision on how a shampoo smells, what color it is, how convenient it is to buy, how much suds it makes, and price. So deciding on a favorite shampoo ain't rocket science either. Use whatever product makes you happy.