I can't say I've ever experienced a need for more speed in a URL shortener, honestly. Neither in the shortening phase, nor the lookup. The auto QR code generation is nice though.
Second that. Speed is not something I ever even considered to be an issue.
If it were me (which it's not), it's the QR code feature in combination with the existing idea of URL shorteners that I'd be promoting as the differentiating factor — i.e. "Qik.im — Short URLs with QR codes". I think introducing the concept of speed into the copy detracts from what's cool about it.
