The M3 has so many features that it is open to be used for illegal purposes, but it's not intended to be used for that and they don't mention it as a feature, so according to the advertised features you don't need to break any laws for the full potential.
There's loads of info on their site, which is
way more than what fischju has on his comparison list. I suggest reading through carefully, and as far as fischju is concerned, updating that list with all the comparable info (whatever isn't the same between them).
http://m3adapter.com/faq.htm