I chose A-2 for my Skookum which will arrive in about ten months or so. I chose it because I have a few O1 blades already, the A-2 blade in my woodworking plane keeps its sharpness longer than the O1 blade I have, it seems a bit tougher and like you said, it should be a bit more corrosion resistant. Either way you'll win, but I kinda think A-2 has the edge (pun intended).