I recently switched from a +35 degree synthetic bag to the Marmot Pinnacle and I couldn't be happier. Doing most of my camping in Colorado (aka - at elevation) means that +35 degree bag I had involved also wearing multiple layers on top and bottom, my down vest, wool hat, gloves, etc, along with a sleeping bag liner. Even in mid-summer, it made me not want to go camping.
The Marmot Pinnacle, however, has solved my problems. This is, by far, the warmest and most comfortable sleeping bag I've ever used. The first test was sleeping under the starts in Teton National Forest at the start of October. It was chilly (low 40s) when we set up our bags, so I put on my usual (down vest, wool hat, gloves, etc) and hopped in my Pinnacle. Even though the temperatures continued to drop throughout the night, I actually found myself being too warm and needing to remove my hat and down vest. I couldn't tell you how happy that made me. Also, when we got up the following morning, our bags were definitely a little damp...but that didn't take away from the incredible warmth the bag provides.
The stash pocket is perfect for chapstick/other small things you don't want to accidentally roll over on in your pockets and easily tucks away into the draft tube.
I'm 100% sold on this bag!
A little about me and sizing:
I'm a 5'6" female. I went to a local store where I could hop in a few different bags, as I was debating between this or the women's version. For me, the women's bag felt a little cramped. (I'm that person that completely untucks all the sheets when I get into a bed.) I decided to go with the men's regular, even though there's a bit of room down by my feet. It gave me a little more space and, like I said above, I couldn't be happier with this bag.