Thanks for the great review. Just looking at the pole design it is obvious that triangle of poles on the roof will collect snow like a bucket. What were they thinking? There are good reasons the two-pole tent dominates the market.
Speaking of 2-pole tents, you mentioned a competitor for the Assailant, the BlackDiamond HiLight. I own one, and I must take exception to your statements about leaking and breathability. I spent a rainy night in one in temperatures hovering around freezing, and the epic fabric did not leak one drop. Condensation with two people in the tent was never more than a thin film of droppless moisture which could be felt with the bare hand. All other moisture vented out through the epic. In fact, eventually I zipped the vents closed to trap heat, and it still continued to vent. It is so air permeable in fact, I could feel wind coming through the fabric when the wind was really gusting.
I do not think the paper thin epic fabric is durable enought to be called an expedition tent; but it is great for the UL hiker in occasional alpine/mountaineering conditions; and after reading this review; I must say, still a better choice than this SD Assailant.
About $300, or get it at REI as I did for "free" if you know what I mean ;)