Plastic boots were the way to go in February. I tend to use them a lot because they are warm and fairly comfortable. They also fit my skis. My lighter step-in compatible boots aren't very warm and they aggravate an old Achilles injury.
Having said that, the plastic boots were overkill on Friday. They really sucked downclimbing the Final 400 and bushwhacking below the E-ledges. It was pretty warm. I'm a wimp about cold hands, and I went without gloves at least two thirds of the time.
I have some decent boots that would work with strap-on crampons, but my strap on crampons are older than most of the people on this board, and they are terrible.
