I can't speak to OTLs but in my experience, high power push-pull has the greatest potential for communicating the enthusiasm of a live event. There are many attributes coveted by audiophiles that have little bases in live music - precise imaging being one of the most obvious. On the other hand, live music presents tremendous dynamic contrasts compared with audio. Low powered amps like SETs tend not to fare too well in this department. And while powerful solid state designs are dynamic champs, there are just too many other areas in which they fall short.