I have Joule Electra OTL monoblocks, and I agree with Glide 3 that the performance is somewhat speaker dependent but on suitable speakers, the performance is stunning. I am unfamiliar with the Kharma speakers, but basically, OTLs work best on speakers with higher and relatively stable input impedance loads (definitely above 4 ohms and preferably in the 8 ohm and above range). As for specifics about the sound? My experience is that the OTLs have an extra special "purity" and "clean-ness" that on well-recorded material really makes one appreciate how beautiful music can be. Can other amps of different but well-executed design do as well? They're so many good ones out there that the answer probably has to be "yes." I've just not heard them, so for now, it's the extraordinary purity of OTLs that makes the difference to me.