Magneplanar Listening Comparison 1.7 vs. 3.7 Speakers

What does "acoustically smaller" mean?

3.7 owners are going to love this discussion. ;) 

There are many justifications for audiophiles opting for the lesser speaker, and this is one of the most obtuse I have seen. :(

who advocated the smaller speakers and what reasons were obtuse?

I've always felt that the 3 series Maggies were the sweet spot in the line up. The smaller one's sound a bit bright to me. If your budget and room can handle them, I'd suggest going for the 3's.

In my experience, for a given manufacturer and model line, a bigger - and naturally more expensive model, will always sound better given enough room to breathe and fed by the appropriate amplifiers. You clearly have enough room so it's a no brainer that 3.7i is the better choice if cost is no object.