Just got one of these... darker than rb500, really cool and detailed low end.
Build quality is good as well
So far i've used it on an acoustic guitar and a lead vocal, requires a LOT of gain and a good EQ to get the top end out (i'm using a Tube tech Pultec Clone)
I't also looks amazin, I'm telling people it's 2k mic and everyone seems to agree...

Really worth the money....
I also own 2 rb500 wich are becoming my main guitar mics...
one funny thing... the rb700 wooden box states RIBBON MICOPHONE.... stupid chinese