IC_Rafe - agreed - the received wisdom that a down sleeping bag becomes unuseable when even the slightest bit of moisture falls on it seems to be unkillable. Its even in a gear guide published by Trail Magazine this year, which also reckoned that the best synthetic insulation 'is almost as efficient as down', something PHD would have issues with! In reality, the people who use down bags dont seem to have a problem, but I notice a lot of people using synthetic bags using moisture problems as a justification.
Last year, Wayne said this about his down sleeping bags in reply to someone saying they would only use synthetic -
http://www.bushcraftuk.com/forum/showthread.php?t=128711&highlight=mountain+warehouse
In reality, nobody wants to sleep in a wet bag, even synthetic. If your going to be in very damp conditions, then go for synthetic - thats sensible. But for most people, down is fine, and packs down smaller and lighter. Just do what we all do - use drybags and common sense. They are more expensive, but last longer, and are generally cheaper than than they were 20 years ago - Alpkit's SkyHigh 700 is back in stock, and at £150, is a great deal.
As for Wiggy's, when I looked in to them, their fans seemed to be almost cult like in their defending of them. But they are really heavy, not exactly cheap, and have to be imported from the US, so you have no chance to try before you buy. And if you dont like it, then things can get sticky.
I think Wayne's advice in that previous thread was spot on: