I use this jacket in combination with Beyond's Alpha Aura fleece as a versatile layering combo for camping and dayhiking and I have absolutely no complaints. It does a great job keeping wind and light moisture off, it packs down reasonably small, and I like that it has handwarmer pockets.
One criticism I might have of it is that it's relatively heavy; 12ish ounces vs 7 or 8 for BD's Alpine Start. However, there are a few reasons I picked the Ventum over the Alpine Start. First, I don't bring softshells backpacking and the difference between 7.5 ounces and 12 in a daypack is essentially nothing in my mind. Second, without having actually used an Alpine Start in the field, my impression from reviews online and from briefly fondling one in my local mountaineering shop is that the Ventum is likely a bit more durable. Lastly, the handwarmer pockets are a must for me in this type of jacket, as I find them indispensable for lens caps, filters, release cables, and other sundry small photography items.
As for fit: as I wrote above, I layer this over an Alpha Aura fleece (both size XL) and have had no problems at all with fit. I'm not a small man, nor am I in particularly good or bad shape; I'm 6'-1" and about 220lbs with broad shoulders and a deep chest. I would have to be pretty significantly fatter than I currently am (and again, I'm not exactly a bean pole) for the jacket not to fit. All of this is to say I'm not quite sure what to make of the other reviews talking about poor fit. If you have even close to an average build, I'd be surprised if you have fit problems.
Overall, I'd highly recommend this jacket to pretty much anyone that spends significant time in the outdoors.
