An interesting theory and a very nice solution to the problem it posses. I like it. :D
Boiler temp control is easy to obtain down to the tightest specs you could ever want for pretty reasonable prices now-a-days. The tough part is getting the whole grouphead to the precise temp you want and maintaining it. Itll be interesting to see their solution. :)
If they solve the problem of grouphead temp and stability as nicely as they did the pressure problem it would be a sweet machine to have!
Java "Watching the temps" phile