Yeah, i dont know why they didn't use the same (internal) pump system as in their synmats...perhaps they will? someone was talking here a while back about the thermarest model coming out (Neoair) similar thickness, very light and compact. I mainly went with synthetic (synmat) coz a few people use them(mine) and I can see people getting jack of the pump and just blowing in them...condensation etc.
Really the pumps just take that extra bit of patience...the sleep is unmatched

better than at home!
The down would have to be the ultimate snow mat', synthetic warmth seems about similar to a self inflater.
My only concern is punctures (had one in the down-mat,it put meaning to the words...),
Exped also sell multi-mats'-I got one and cut it in thirds (they're 2mx1m) and take it as a sitmat and emerg. warmth/backup. Full size they would make a good ground-sheet and keep the whole tent comfy and warm.