Hard to say. I own both, but haven't used the S30V enough to wear it out yet. Many guys are very happy with it. Most knife makers seem to still prefer D2.
I have used a bunch of the tool steels like A2, D2, O1, and L6. They all hold an edge great and are very tough. The latter 2 rust fairly easily if not maintained, but perform well beyond good.
I have used many of the knives TB speaks of. Victorinox, Forshner, Dexter Russell, and the like. I don't carry them afield, but use them to butcher after the game is hanging. They are basically commercial grade kitchen knives, sharpen easily, and don't cost much. The Russell Green River carbon blades are great for this also. I did 2 deer with a customized Green River Ripper this year. Then made some jerky with it. They would make a superior set of steak knives, IMO........
IMO you can't go wrong with D2 or S30V. That said, I field dressed 3 deer with good old 1095 this year, and the blade is still plenty sharp for round 4...........