Yeah, the 2db was a for the PT only, and for a 6V6 amp, that is the place to start. The bigger PS cap should do much for improved transients as well. But still, to get the most out of the PT, you need to change the OT as well. To get the most out of the OT, you need to change the PT. He said he was not able to afford a Red Fang (I got my first for $129 new delivered, boy was I shocked when I went to get another one) so price was a consideration. If the sound of the new higher efficiency speakers suits his needs, I still contend that a speaker change is the "most for least" option.
Then he said speaker and PT, Oh Yeah. And with the weber PT offering higher voltages, maybe the Allen Deluxe OT is a better choice if loud and clean is the target. It would be the next step.