Since DL's assumed control of NW, the planes from DTW to LGA, DCA and BOS have gotten smaller and the % of First Class seats larger. You'd think this would increase upgrade opportunities, and yet while Silvers had little trouble upgrading on NW, Gold and Platinums aren't always making it on DL.

I presume that more PMDL flyers are traveling through DTW than one would lead to believe reading FT (in which most PMDL flyers claim to avoid DTW).