Two sets of poly pros or one?

Here is a good (high-level) comparison on synthetic vs down. Darwin (and others) seem to rate the Apex synthetic layer. Enlightened equipment has some good gear - both synthetic and down. https://www.youtube.com/watch?v=ijHgkoq3sM8

Maybe getting off topic into jackets, but I've been happy with one of these synthetic (Climashield Apex) jackets from Cumulus in Poland as an alternative to a lightweight down jacket: http://sleepingbags-cumulus.eu/uk/categories/jackets/climalite-full-zip-466389?gid=55&vid=1 Warmth for weight and packability seem similar to a lightish down jacket, but I can be happier pulling it out and wearing it when it's cold and damp. The problem I feel with down jackets is they nearly all have sewn through seams so lose a lot of the effectiveness of the down, plus they're no use in an emergency, getting cold and wet situation, they're only of value as a comfort in a hut or tent or keeping warm when sleeping if your sleeping bag is a bit light. If you want a really warm down jacket, this one is up there, high end down, water resistant outer and about the only one I've seen with full box wall construction throughout: http://sleepingbags-cumulus.eu/uk/categories/jackets/mens/neolite-endurance-636069?gid=10&vid=1

If there's rain in the forecast, I take a permaloft (synthetic down) jacket as my third jacket this time of year, rather than my thin down jacket. One time I walked out over Mt Thomas from Pinchgut Hut and it began snowing lightly which turned to rain as we descended to the car (thank god). Since then I've taken the permaloft for peace of mind. It was so cold even though I was wearing my parka, I had to wear that extra jacket over the mountain as I'd forgotten to take my polarfleece jacket and needed the extra layer of warmth. If there's no rain forecast my extra jacket is the thinner down jacket (plus the thick down jacket) at this time of year as I do feel the cold. It's good to know that I'll be warm enough. We've been sleeping in unheated huts and waking up to ice on the surface of the water bucket inside the hut.