Very nice!

And then I digress a bit...

The section about the historical relevance of the LFE channel is good, especially if you consider that the E stands for effects and not for program (speech and music). In fact, some music recording companies do not use the LFE or sixth channel at all for that specific reason. This is not to say that you may not need a sub, though. A sub is a sub, LFE is only a channel.

There MAY BE another reason to have more subs, and that is tied to the acoustical behavior of the (smaller) space. It turns out that having a sub 'up front' close to the main loudspeakers, but still coupled to the room, and a sub to the side is a good method to find complementary modal responses of the room. I have heard this, and it is quite convincing.

The Rel approach is convincing in that sense too: they almost claim that for a smaller room it is better to get small loudspeakers and then just one or more subs, as that way you have control over the low end. Well, I guess you could do the same thing for less by bi-amping a full-range loudspeaker, although it may be more effective to have separate control over the very low frequencies from a room-acoustics point of view by still adding one (or more) subwoofers. Oh well, it's just money ;-)