Those look pretty good, but I've never heard of them. Lundahl trannys are good. You will need a mic preamp with 70-80db of gain for acoustic music, as ribbons have really low output. But, good thing about ribbons, they can take a lot of SPL before overload.. notice on those rated 165db at 1% distortion.
Blowing onto a ribbon mic can be critical, or even walking fast with the air pushing on the ribbon. You don't want to put it in front of a nimrod and have them blow on the thing and say, "is this on?"