I learned that the previous PP models might have several differences from the current ones, but basically the design hasnít changed. The fabric might be slightly heavier on the older models & the loft might be slightly less. However some older models are essentially the same as the current ones. Basically the current models have more loft (thus greater warmth) & lighter-weight fabrics. The fabrics used for the shells now are more consistent in color & weight than previous models. Ask about the color---if itís all gray it could be the same as the new ones; if itís gray inside/forest green outside, itís probably a few ounces heavier than the new ones. As far as down goes, it could be the old 750 instead of the new 900---this could be hard to measure since youíd need to measure the loft which is highly subjective.
Unfortunately, I am going to have to pass on this one... I need something sooner than Michael can get it to me, because I just sold my Heresy hammock, and I have no UQ for my Speer!
"We must, indeed, all hang together or, most assuredly, we shall all hang separately." - Ben Franklin