Hi,
Are you going to heat treat it? If not, it really doesn't matter very much. Just use a cutting speed of 80-90SFM and be happy.
If you do wish to heat treat it, either water or oil will work for either. Just not as good as the proper medium should. The thing to remember is that water is a more severe quench than oil. It could cause cracking in O-1. And oil quench may not bring W-1 to full hardness.
To draw either, 400F oven for a couple hours works for me. These are pretty simple tool steels so not much reason to make it harder, (pun intended), than needed.
Once hardened, there really isn't anything to choose from. But if used annealed, I prefer O-1 because I think it wears better. Which maybe all in my head.
Dalee