What's the greatest bargain in SET these days?

Saki,Got it. There are others on this thread that could better answer your question. I am rather new to tube amps.
Further, I wouldn't generalize based on the dynamo and the Frank's. They are both Israel's designs, but there are huge differences in transformers, driver tubes, etc.
For what it is worth, which is not much, I'd say the dynamo is a bit more of a classic tube sound. Lots of midrange bloom. The franks have a richness and harmonic sophistication across the frequency spectrum that is unique in my experience.
I encourage others with more experience to contribute their thoughts.

Brownsfan ,
You are correct. Differences are more than output tube. The Frankenstein has the advantage of bigger and better transformers and power supply as well as better parts, this is very significant. The Dynamo is an excellent budget conscious amp. The Franks are Israel Blume's all out statement SET quest. Very different objectives, the Franks are honestly sublime amplifiers.

Charles, can you offer any general thoughts on el34 vs. 301b designs? It is an interesting question.

Saki, I believe you stated you own the Primaluna Prologue integrated, which I know intimately. I also own the Primaluna One with excellent upgraded tubes from the stock tubes. I also know this integrated intimately. Both my wife and I like the Coincident better with the various Tekton speakers we own, especially the M-Lore. Granted it is a close call, but the Coincident is the winner in our view. The Primaluna is a really good amp, versatile, great tube rolling possibilities; but for some reason both my wife and I think the Coincident is more organic, the music flows better. The tone, timbre, bass and dynamics are better on the Dynamo as now constituted. I admit that I haven't experienced every option on the Primaluna Dialogue. Tim Smith said that the Primaluna is twice as good with KT120s over the EL34s. I don't know? Since the Coincident has only 2 power tubes as opposed to 4 in the Primaluna it's much less expensive to operate with premium tubes.

Bill,
I can't address the technical differences,only the subjective listening. Mikirob actually summed it up superbly! The 300b is simply more natural sounding and thus more realistic. Tone,timbre,harmonic nuance and musical fluidity are superior IMHO. Can a good el34 amp sound very good? Absolutely yes, and better than a mediocore 300b amp. If implemented to a high level I'll choose the 300b option. It inherently is more authentic,richer yet more open with better resolution and transparency. This is what the higher cost tube gets you. These are just my listening impressions over the years.