1) We had the same bills from my grandpas age till mine, and suddenly over the past 20 years we're up to revision 4.0 or so. Confusing the endusers to no end. Although the API has remained constant what you get per bill has dropped quite a bit over those 20 years. Maybe the new 4.0 version should get me more groceries for my $100 rather than less each revision.
2) Same spokesman for each revision confuses upgraders. You got Franklin? Yeah I'm using Franklin. No dude thats the old version of Franklin, has some security bugs, you gotta upgrade before the economy gets powned. Can't they put something contemporary on it, like the Miley Cyrus bill or the 'Bama Bill? Or embed the year, like I got me an "2013 buck" because it has 2013 written in big ole automotive style letters?
3) They're doing a great job at rollout of focusing on the new features, but ignoring the old features. I need to know the API to verify the new bills are legit. A smart counterfeiter would focus solely on the new features and just print on toilet paper or something, half the public would probably buy it. A REALLY smart counterfeiter would start producing a run on version 5.0 $20 bills and most of the public would assume its actually upstream's product, seeing as upstream ships a new version about as often as Detroit ships a new model car now.
4) I'm not kidding around here, why do they use sequential serial numbers when a pub-key crypto signed serial number with a VERY private key would let us look at a bill and verify its a genuine signed serial number? Maybe not prove the bill is legit and uncopied, but at least you'd know its a copy of a good signed bill. They could publish a list of destroyed currency and rotate aggressively such that counterfeits would only circulate for awhile.. Unless of course the destroyed currency was the counterfeit and the cancelled one in your hand is the legit one... maybe thats why they don't do this.
5) As far as .coms go this startup needs a new art director. I'm not asking for kittens but lose the eye in the pyramid and flowery decorations and inkwells and eagles and try a QR code in one corner for vending machines (hey when the 70s stagflation hits and you want to buy a condom for $100 from the local vending machine, you'll be sorry...).
6) This seems to be the only branch that hasn't sold out naming rights. I halfway expect to see "Larry Ellison Bucks" and "HP 20s" at some point in my life. The "3com three dollar bill". As a startup they're leaving money on the table by not selling naming rights. At the bankruptcy Oracle will probably pick up the product for pennies on the dollar and freak out the GPL linux guys who'll fork into a bitcoin implementation on mariadb.
7) I don't think they're getting the tech news buzz they need. They need to send out fat stack of free samples to hacker news readers like me to create buzz. They should send out so many free samples that I can freely share them with friends.
8) Open source the code to generate? Why can't I print some at home to pay my debts, just like .gov does? Information just wants to be free. Speaking of which it needs a license I'm guessing not BSD or GPL not some CC:SA variety?
9) Is the new API compatible with existing players like "wheresgeorge.com" (are they still around?)