Synthetic or Down?

I think I (We) have made to big a deal of the bag ratings by saying "this is the minimum spec" and "with that bag you'll die".....have any one of you ever seen a local with a FA Ice breaker okay ja maybe one that has been "liberated" but the rest survive on 2 blankets and gumboots.Maybe we have grown soft and want to take the Nature element out of our hiking trips.I might be cocky now but I'm gone go with a -7 sythetic bag and a liner and maybe I'll freeze my butt of, but I'll come back with a awesome experience and go buy that FA Ice breaker

My status as employed from the day after my last exam has now been confirmed (accounting is such an awesome profession, there is always a job), so now I'm finally able to afford equipment that isn't bottom of the range and reduced to clear!

Basically what I am looking for is a down bag (mainly due to the weight) that will be usable in spring-autumn, or possibly in the small berg in winter (I lack friends who have equipment/finances to hike in winter, thus winter isn't really relevant at this point in time). I have had a look at the First Ascent and Cape Union Mart website and have been considering 2 bags, the First Ascent Fusion 600 (rated -5C, R2000) and the First Ascent Explorer (rated 0C R1500). I have also looked at the Ice Breaker (rated -8C, R2100, but I suspect everyone on this forumn already knows that!), but I imagine that I would wake up in 3 litres of sweat on a warm summer's night! I am open to other suggestions.

What do you guys suggest?