What would you say is the better sounding SET amp?

Different horses for different courses. Aside from the difference in power output, the tubes do differ in ways that make one or the other more ideal in a particular application. I generally find the 45 tube to have an ideal tonal balance and beautiful sound, without the 300B tendency to be overly lush and wooly sounding. The 2a3 is much leaner than the 45, but it sounds very fast and detailed and has a beautifully extended and airy top end.

In my system, both 45s and 2a3s work well. I am currently running 2a3s in parallel single-end configuration, but I also have a pushpull 45 amp that sounds nice.

This is an interesting thread. I've sort of forgotten about a number of amps that posters here have brought up. I too, like the Art Audio PX-25 -- a nice and lively amp that sounds rich, without being bloated. I also like the Viva Solista.

On the crazy expensive front, the Audionote Gaku-On (211?)sound pretty good too.