Sonic difference Vk200 vs. VK500?

Hey, I am looking to purchase a bat and was wondering if there was any significant difference, besides the price and wattage between the VK200 and VK500?
I own the VK-500. A good friend of mine has owned both and reports that the 200 is perhaps even a bit more musical than the 500, although he likes the significant headroom that the 500 offers. If you don't need the power, the 200 is a great buy.
I should just add that the 200 is no chump in the power department either, but the 500 w/BAT-PAK will drive any speaker made given the juice to do so.
I haven't heard the 500, but I own the 200 and it delivers all the musical power I need for my B&W 802's. You will not regret buying the 200. I do not understand why people sell them!