But besides efficiency, i'd also like to see RF interference measurements on this one. There is a reason good power converters are fixed in one voltage output and use transformers...
High. VHF AC to DC conversion isn't in many devices because it is actually hard to get it to not cause issues with everything else on the same transformer (not even breaker).
Also you notice they use a lighter wire than most laptop power supplies would and no ferro loop at the end to reduce the noise to the device.
Maybe I missed it, but I don't think I saw a UL approval on the device. I also don't think there is enough room in the case to have a thermal cut out, and a fuse/breaker. Which you really need on a power supply.
I'd love to be wrong on all this. I hate carrying a brick (though mine is about the size of half a deck of cards).
The real thing for size is the transformer and other magnetics, which decrease with frequency, hence why this uses VHF frequencies. Output filters can also be made smaller at higher frequencies, and Ken Shirriff's iPhone charger teardown above shows a small ferrite ring _inside_ the charger case for high frequencies.
UL Approval is probably under on the "Production Timeline" (2/3rds down) under "Submit for initial regulatory certification (4 months)", which is set to begin now (Apr-May).
As for the wire thickness, it doesn't seem that much thinner than my Macbook Charger, which is also 65W. The production timeline on the kickstarter leaves them time to change to a thicker one.
The big question of course, is the feasibility of the VHF AC-DC conversion. FINsix have a paper (http://finsix.com/assets/files/FINsix_Tech.pdf) but its not very long or detailed, and I don't know enough to criticise it if it was.
[1] http://www.righto.com/2012/10/a-dozen-usb-chargers-in-lab-ap...
[2] http://www.righto.com/2012/05/apple-iphone-charger-teardown-...