I have built one and can say it is very nice, I would like to see ozqrp release the code so it can be modified for special needs, but for now I will use it for a new BitX60.
I can think of several applications for a VFO of that size and versatility. It would ideal for in a BITX transceiver since the fixed output can be used for the BFO and the tunable output used as the VFO. This could turn a 20m BITX xcvr into a rig for any desired HF band; possibly even a 6m xcvr. Another use might be found as an antenna sweep analyser provided one can modify the code within the microcontoller. When I get my hands on one of these I'd like to install it within a PSK31 transceiver that I built for 80m. The plan is to get it functioning well on 80m before tackling the other bands.