The biggest place where the little one π's and two π's are outdone by the bigger speakers is in dynamic range. You're right that the tower two's have great bass response and that their top octave extension exceeds that of the larger models of π speakers. But the large format π's just sound bigger.

So I like both the tower two π and the Thermionic three π Speakers, and I'd be happy with either one. For the money, the tower two's are definitely great speakers. They are also attractive because of their size, and they fit well into many living rooms and home theater settings. Nice, deep room-filling bass, sweet, full mids and crystal clear highs. But the Thermionics are more like the other large-format π Speakers, in that they just sound "bigger."