In reply to Saor Alba:
You need to better define "ethical". What does that mean? Either a goose is killed and the down plucked from its burnt and possibly waxed carcass or the bird is plucked while live. It's a lot more complex than "ethical" and "not ethical". It is illegal to sell down plucked from live birds in the US and the EU and so all the brands you list are arguably as "ethical" as each other.
For what it matters, Patagonia head up the International Down Task Force (which I am a member of) which aims to promote good animal husbandry and stop any sort of live plucking. I'd put them in the same camp as ME and Alpkit ('good'). I've visited Rab's source factory and it's 'good' too. North Face are too clever to kid their customers because they know the business they'd lose if they were found to be being nasty to little birdies, so they're 'good' too.
HOWEVER, what happens when bird flu comes along and kills off all of China's birds, as it did a few years ago? Maybe the ethics go out the window and the Chinese suppliers tell no one...? The point I'm trying to make is that "ethical" needs to be well defined and it is a very complex issue.