My fatheads are Open Plan Recording Fatheads, but they are very similar to Cascade's, I love them on Guitar cabs. I have used then on acoustic guitars but they have a darker sound than a condenser so they take some getting used to, but when you use them on an acoustic that is recorded along with the vocal, the fathead rejects the vocal from the guitar track well. + 1 on having a good sounding room.
Alan.