I've had an Atmashpere S-30 for a short while. Really like their OTL sound. I still have a Red Wine Sig 30, actually the Omega version which is the 30 wrapped in wood. Have not heard the others you mention. The 30 is the one for me. I especially like the fact that it is battery operated and I'm off the grid. My taste for amplification has been in the SET camp for the last 2 years and the 30 is very close to that. I think ultimately, besides personal taste, it comes down to the amp/speaker interface. Some speakers like some amps more than others. Good luck.
