Mont BellSpiral Down Hugger #3

[multisportscott]

Hi from New Zealand,
I noticed that Aaron Teasdale and Jeff Boatman both use this bag in Aaron's article in Mountain Bike magazine. Backpackinglight.com recommend this bag also but it is not one they recommend for "slender" users. I imagine that Aaron is slender, and Jeff "looks" slender in photo's!! Do you guys find this bag warm enough even for a slender build? I fully understand about beefing up the temp range with additional clothing etc. But I don't want to waste energy warming up dead space.
This bag seems to be excellent value and ticks all of the boxes, even purchasing with the New Zealand Dollar.
What do people think of this bag?
Cheers, Scott