Okay so I got the chance to try out both the venta mx and the sv. The sv is noticeably heavier than the mx for obvious reasons. The cut of the mx is longer than the sv both front and back. I would say that the mx has a closer/trimmer fit than the sv in all the areas of the body (chest, waist, arms). The arm length of the mx is a tad bit longer. As far as the materials go. The sv incorporates 3 windstopper fabrics and is a more burly jacket than the mx. The mx has a stretchy windstopper material in the articulated areas (shoulders and outsides of arms, and back). The stretchy windstopper material screams quality and is probably why the jacket is $50 dollars more than the sv. The chest pockets and pit zips use water tight zippers which are used with more of arc'teryx' hardshells. These zippers do not glide as easily as the zippers used on the sv, but offer better water protection. My main reasons why I like the mx more is because of the trimmer fit, extra coverage, and the storm hood. The drop hood of the sv works great with a helmet, I just found that the storm hood offers an even better fit with a helmet as well as more face protection. I am tall and lanky (which the venta mx accommodates this body style very nicely) 5'11" and weigh 125 lbs with ~35-36 inch chest and the mx in a small offers room for layering even though it has a trimmer cut than the SV. The MX is a bit more breathable than the SV due to the less heavy materials used, but the sv provides more warmth. The mx is very lightly insulated but has enough to be used as a stand alone piece in fall/spring conditions with a long sleeve base layer. I got the brimstone color, and it is BRIGHT ( I wanna say it is a bit brighter in person than the picture), which is great for being visible on the slopes or anywhere.