I think it's a bit of a stretch to call the Mountain a "concept album," personally, just as I wouldn't call Octavarium a concept album really. At the very least, the concepts aren't obvious enough to take away from the listening experience for me. For whatever reason, I think it works well enough with Scenes, but tends to annoy me more with Aquarius and Visions. But if that's the direction they're going for, then all the power to them.