I looked at foldables before getting a rollable marine panel for myself, at about 2 pounds it puts out 20w, 15.4 operating voltage,1.2amps operating current (from the container) and is 1'by 2' and can be rolled into approx. 4" diameter. It's for marine purposes so it's also waterproof (weatherproof,on the box). It fits into my Arctyrex sling bag so its fairly portable, althought not as flat as some foldable types. Runs a gps ,can run a 12v fan/led combo with power to spare and could trickle charge a laptop, probably run a small dvd player, power/charge cell phones etc, and trickle charge a car battery. If the power goes out very handy for myself, and others.
I have a Vector battery pack that can be charged with the panel so if the power goes out long term I shouldn't be without light and ventelation. If your buying panels it would be worth the investment IMHO to go the extra length and get something with similar benefits, unless all you need is a pair of AA.