Are you thinking about adding two more M22s to the front for the "effects channels" of the 1400? I have 5 front speakers including the center and the two "effects" speakers and of course the mains. I really like the front "effects channels". It give the movie that big theater sound without having to use some of those cheesey DSP modes.
If you are going to use the M22s for this purpose, I think Yamaha recommends that the "effects" speakers be placed above the mains and about 3 feet to the outside of the mains. I have mine 2.5' above the mains and it works out very nicely.
I haven't tried the back surround channels yet so I can't comment on that but it seems that if you already have 2 of the remarkable QS8s for side surrounds.... well, from what I experienced (at sushi's house), I would argue that due to their dipole nature, they do a good enough job of "wraping the sound/enveloping the listener" that the rears aren't especially needed. But no doubt it would be cool to have them.
However, from what I've read on other forums, you can't have both the rears and the "effects" channels at the same time with the 1400 unless you use a separate amp for one or the other. Not real clear on why or how I just know it involves the "zone out" feature.
*Does your train of thought have a caboose?*