Frenzy, just as with picking a Mother Ship, the 'pros & cons' can vary quite a bit depending on how (and how often) you plan to use the boat. There's an excellent post on using a Portaboat on the SSCA Discussion Board tho' it is slanted to full-time use as a cruising dinghy; you might find it useful to you.
http://www.ssca.org/sscabb/index.php...=1196&page=0#2
This dinghy choice reminds me of a bi-polar distribution (if that rings a bell for any economists or statisticians in the group). Most dinks are a compromise wherein their construction and functionality meet most needs pretty well, and they suffer from few extremes. Portaboats seem bi-polar; their pros (e.g. well wearing hull material and stowed dimensions) stand well above the other choices while their cons (longevity of the bits & pieces or rigging one on the deck of a smaller boat) are near the bottom.
Choosing the 'right' dinghy is even harder than choosing the right Mother Ship, I think.
Jack