Arcam vs Marantz vs NAD receiver?

I am buying an AV receiver that will be used for music at least as much as movies. Speakers will likely be B&W M-1 Sats and PVD-1 sub. I am looking at Marantz SR 7007, Arcam AVR 400 and NAD 758. All have different specs but don't bench test that differently. I have heard all three and liked them all, but I am concerned about the Arcam and especially the Marantz running out of steam at higher volumes driving 5 channels. The NAD to its credit hardly loses any punch even driving 7 channels. Marantz has the most features, but the lightest amp section. Your thoughts?

kn