Erick L, I have not seen or tried them in real life. Also, I shouldn't have used the phrase "serious backpacking", as there are many serious backpackers who have overbuilt packs like those. However, as a backpack for my uses, the Backcountry model offers a limited daypack-like capacity and many superfluous features for a substantial weight penalty and 4x the price of my current pack. I would not like to haul it up mountains. That said, if I had loads of money and wasn't so into the ultralight-ethos Panpack's products would be quite appropriate.

I've sewn packs before and I think an ultralight pack which could be divided up similar to the Panpacks may have moved up a few notches on my projects list.