Marmot's Pinnacle bag is a far cry from my first cheapo sleeping bag. It's sumptuously soft and luxurious, and warm; in fact more so than the duvet on my bed! It's filled with 800+ fill quality goose down and has a host of technical features. It also costs a lot more.
I always forget that price is at the top. To me anyway it would make more sense to put it at the bottom with the rest of the spec, for no other reason than that’s where I seem to always unsuccessfully look for it.
It is worth noting that down will last a lot longer than synthetic insulation. Synthetics eventually loose their loft, whereas a high quality down bag, if well looked after, should last a very long time indeed.
Also at 1200 grams the bag is way too heavy for summer alpine climbing.
A sleeping bag with a total weight of 500g should be more than enough. Saying that there are very few summer alpine routes, which require a bivi, that I would bother to take a sleeping bag on.