Well, of course it's "a bit much". "Perfect" usually is.
You don't need "a perfect room", but since the LFR's radiate in more than one direction, it's more likely that you're going to place something in the room that affects them. If you have a couch or a wall unit (or no wall at all) behind your M80's, it's much less likely to noticeably impact their performance.
The room is important. And I live in the real world, not the land of "should". If I were going to invest in the upgrade from the M80's to the LFR's, I'd make sure that my listening experience wasn't compromised by mundane concerns like extraneous furniture in the room or the architecture of my house.
Lots of people are lucky to have dedicated listening/viewing rooms that are nice, uncluttered rectangles. I'm not sure whether to envy or pity them.
I guess ultimately, I'm with Boltron. I've never heard the LRF's and I'm sure they are magical in even an "acceptable" room. I'm also sure you could set them - or any other speaker - up in such a way that they sound dreadful.
