8 inch woofers are not to large for small room with Harmon curve designed speaker coupled with ARC. Integration with sub is seemless.I am very interested to hear back on your thoughts. I suspect you may be venturing into the area of diminishing returns.
I am in a similar place in that I have BMRs with RAAL tweeters and Revel F206s. Once optimally set up, with room correction applied to the bass frequencies, I do not have much of a preference. I can hear a difference in midrange and high frequency response, but I cannot hear any difference in any other dimension at the MLP.
This is not an audible thing for me, but RAAL tweeters do product higher distortion at high SPLs, but I do not listen loud enough for that to matter (average in the low 80s with transient peaks in the mid 90s). The additional bass driver in the F206 theoretically allows for lower bass distortion, but with dual subs crossed at 80Hz, this point is most likely moot. So, the only concrete advantage the F206s have is a couple dB better sensitivity.
As for the sound of the tweeters, there is a perceptible difference between the ribbons and domes, but I like them both. I have never heard a Be tweeter that made me want to open my wallet as compared to other materials. Perhaps I am wrong about that?
It is good to see the point made that bigger speakers placed in smaller rooms simply complicate room treatment and correction rather than actually sounding "bigger," unless there is signficant low frequency extension offered by the larger drivers.