I would recommend toe points but I agree it can be done without. You certainly don't need toe points or rock shoes in the summer - footholds (mostly tree roots, see photo at http://www.summitpost.org/mansfield/243051
) do exist. This is not waterfall ice climbing by any stretch, but I'm accustomed to using toe points.
The trail is marked by blazes on trees - below treeline there are only a couple of spots where you could lose the trail, and you'll probably realize your mistake pretty quickly, even if you don't have other tracks to guide you.
Above treeline, the blazes are on rocks, which won't help you in winter. There are some cairns, but they're small and infrequent, nothing like on Mt Washington. On the north side of the summit cone the terrain is actually somewhat easier than at the bottom of Hell Brook, but there is potential for major fall exposure if you wander away from the safest line (and by "line" I mean strange zig-zag route). If the weather is foggy you will have trouble knowing where you are, where to go next, and where to avoid. If you're not comfortable scouting scrambling terrain above treeline, you should either take a different route (like sunset ridge) or have a hair-trigger for turning around.