Gar.

A quick model suggests the Gamma 10 works well in cabinets from 0.5ft3 to 2.5ft3 tuned to 50Hz, and that cabinets up to 5.5ft3 can be used with lower frequency tuning for an EBS alignment. A nice curve results with cabinets of 3.5ft3 to 5.5ft3 tuned to 40Hz, which gives a -3dB shelf from 100Hz down to 35Hz. The extended shelf goes deep and doesn't result in much reduction in output in the bottom octaves. So I'd say you're right, that the Gamma 10 could be expected to work pretty well in tower two π Speakers.

The Gamma 10 might work in the eight π Speaker too, but I'm not sure I'd want an EBS alignment for this one, since the BR extension is already reduced in relation to midrange horn output. But it might sound just fine.

I have tended to skip Eminence series for no other reason than they have so many products available. I've tended to choose lines that have double power ratings. Eminence has a part available about every 100 watts, I tend to go for doubles, like 100w, 200w, 400w, etc. But the fact that I don't use a particular part is only because there are so many, and isn't necessarily an indication that I don't like a particular speaker. The Gamma's are probably quite nice.