Pros: Ridiculously Warm.
Cons: Tough to stuff into stuff sack.
This is a great mat. The pump does take a while to inflate the mat, but even at 17,000 feet I felt the effort required to pump it was well worth the comfortable night sleep. I coupled this with a Marmot CWM -40 degree bag, so I was toasty the entire trip (-20F was as cold as it ever was in the tent).
My buddy had the downmat 7. That worked well for him. In hind sight, I would probably use the downmat 7 and save some weight. These things are so warm it would have to be ridiculously cold before you would be uncomfortable. We did bring foam mats (and used them with this mat) for use in an emergency in case our Expeds popped.
Another thing I love about these mats is that they really hold their air. We stayed at 14,000 feet for three consecutive nights and I never had to re-inflate the mat.
One bad thing about the mat is that they are very difficult to get back in the stuff sack. The way the pump is situated, it can be difficult to get all of the air out of the mat. You absolutely must take off your gloves to stuff this mat, and if you are using this mat in the sub-zero temperatures it is intended for, your hands will freeze. Tearing down camp and all of the stuffing that goes with it is a real pain.
Also, I've been backcountry camping with my wife and kids for years. We've slowly graduated from foam pads to smaller air pads and finally found the Exped mats. We all have one of the yellow summer mats and finally sleep well in the backcountry. Exped has taken backcountry comfort to a whole new level.