Good all arounder
I have the 03 version of the 2nd Dimension it came without the draft collar which I think I would like to have. It seals in your body heat well, but the newer ones probably does a better job. I have used it in single-digit weather and it held up ok. I had to put on my polypro once it got down to about 10F. It tends to generate some cold spots that alarm you when you roll over. But, in its normal range rating, it does just fine. I like it because my big feet (size 12) have plenty of room to wiggle in the foot box, and the expander makes a nice regulator when things get a little to warm, or you are backpacking with varying tempts and elevations and need that regulation power. Plus it expands well enough to be able to insert another dimension bag in it. It is light enough to be carried for the long haul and compresses nicely. I had to by a regular compression sack for it because it only comes with a stuff sack and cotton bag. All in all a real good and sound all around backpacking bag for the money.