Richard,
I'll be sure to let folks know what differences the modded B-200s make. I suspect that high frequency dispersion is less of an issue in an OB configuration as you are getting a good bit of HF reflection from the backwave, and thus the beaming isn't as noticable.
In all fairness, the B-200 beams much less than one would think for an 8-inch single driver, especially given that it doesn't have a whizzer, which is testament to a very sophisticated and well considered design, but the fact is, at least in my room and setup, there are HF hot spots and a relatively small sweet spot. I say relatively because it is actually dsomewhat wider than my Abbys with the Fostex FE-166e's with the smaller diameter cone and whizzer (which will also be getting a phase plug treatmeant as well.)
It will be an interesting experiment if nothing else. I also asked Dave to make my plugs out of either maple or spruce and finish them in natural wood with no stain or paint, and he reports that they look incredible, and his wife said they are the best looking ones he ever made, so in the Revolutions with the quartered maple baffle and Italian Red Gloss sides, and the whole thing sitting on a 4" thick solid maple platform with big Mapleshade brass footers both under the platform, and between it and the speaker, the whole thing should look, as well as sound, pretty nice.
And just to add to the picture -- for at least a while, the speakers will be driven by the Music Reference EM7 amp.
-- Jim