I subscribe to this theory. I had purchased Alphaflys Next % (should have purchased Vapor) and was recently given a very gently used pair of Zoom Tempo Next %. Will race in the Tempo. Has the elements of both super shoe AND the traditional. A hybrid if you will. Alpha Next % was just too squishy and sloppy. It doesn't have the great feel/ride that the Tempo does. The extra weight is mainly in your head. A lightweight trainer often makes for a fantastic racing shoe.
Again, the extra weight is all in your head. You don't think about it, you won't notice it. You don't think/notice weight when you are training in your trainers - you just run.