IMHO taking it down makes little sense. Being able to enjoy BD quality without having a BD player or having to download an inevitably larger, less 'desktop-friendly' file is a nice touch, so it would nice to have that option, but even if you don't think so, and can't tell the difference in quality between the AVCHD and the MKV, taking down what has already been released will just make it harder for people from here to get their hands on it for a short time; it's in the wild and will eventually make its way everywhere, and it's likely enough that the Bluray would itself be converted to MKV and shared in that format regardless (I have seen several different MKV torrents of the 1.0s).