Just how many options does 1 need in a 2 way bookshelf design?

This forum is of no use. 

Feel free to never  grace us with your presence.

OP, I think you'd feel more at home here: http://cheeseforum.org/forum/index.php

The 6” 2-way is the most versatile and practical speaker design for home stereo is why.  A 6” woofer can go deep enough to blend with a sub, and high enough before breakup to match a dome tweeter and maintain good off axis linearity.  Bigger woofer 2-ways of yesteryear had midrange issues or larger tweeters that couldn’t reach the top.   

Andrew Jones talked about his considerations for speaker design in general, that are bass, size and efficiency.  The debut product, Sourcepoint 10, he comes up with after joining MoFi turns out a good balance of these imo.  With the 2-way concentric driver design, he was able to squeez larger 10" woofer into a larger cabinet comparable to Tannoy Eaton to enhance the scale of music that would otherwise be difficult reproduced by a normal size of bookshelfs or stand mounts.  According to a reliable reviewer, this speaker also images quite well, leading me to believe it will handle more complicated genre of music like classical well.  Although not superly deep, the bass is rated 42 hz at -6dB. I don't like a designer purposely boost the midbass in order to get better low bass extension.  Its efficiency/sensitivity just passes 90dB, not superly high but is high enough to be considered high efficient speakers.  I actually have a concern on a speaker with extremely high as 94dB or above because the noise floor of the amp can be audible.  All these design elements were finetuned to sweet spots in SP 10.