There are, of course, a few drawbacks with aluminum. First, over time, the aluminum wears down. For awhile, as the metal spreads out, that's actually a good thing, offering more surface coverage, but eventually it loses its effect. Second, I don't like long hikes on aluminum bars, not only because that wears them out, but also because it is uncomfortable. Third, aluminum really isn't a whole lot better than studs when you're clanking around in a boat or a float plane, though it is more raft-friendly than pointed spikes are.