I still have about a hundred feet of aerographic double x in my fridge - unexposed end rolls from an aerographic photographer. It's coated on a 2.5mil estar base - way too thin to use with a conventional 4x5 or 5x7 holder (for comparison, tri-x 4x5 sheet is coated on a 7mil estar base). The only way to use the stuff I have is with an adhesive holder. It's a truly unique film. It doesn't seem to have any anti-halation backing as specular highlights exhibit halide migration effects. Also, no shoulder at all which, if handled in a non-hamfisted fashion, can yield beautiful prints from high key exposures. In my experience, prints from xx negs souped in pyro appear even sharper than my prints from pyro fp4 negs. It would be interesting to see how much of an effect, if any, base thickness has on resolution.
Has Mr. can ham confirmed base thickness?