Did almost all my winter 46 in a pair of Sorels and loved them - comfortable, warm, and you can actually use them out and about, unlike plastic mountaineering boots.
But, as was mentioned, if you're doing a route that requires crampons (a slide, for instance), a plastic boot with an immobile sole is the way to go. Yes, I've experienced "shin-bang" with them too, on long, gentle approaches. Just leave the laces loose on the flats to minimize that. The thing about them is that when tight, they put your shin canted forward slightly - great for climbing, not for walking. Kind of like a downhill ski boot, if you've ever worn them around the lodge. Comfortable for walking up stairs, and not much else. So, plastic might be a good option for a trip like Giant, where you're climbing from the car. But something like the Sewards, with its long, relatively flat approach, I'd find a lot more comfortable in my Sorel's.
Anyway, that's my two cents.