In reply to Morgan Woods:
The best ice screw is always the one one that goes in the fastest (minimise pump-panic) and it's the lightest 9 (so you can carry more of them or go light). I've seen these Salewa racked up, and 4 or them take up all your gear loop, leaving not much for anything else. I haven't placed any, but they look a faff to deal with.
In my opinion the best ice-screw is the E-Climb and the new lightweight Petzl ones. The advantage of E-climb is that 4 new replaceable tips cost under 30euros, so effectively getting 4 news screws for that prize. That's hard to beat really.
I always carry one Grivel 360 as they are unique for difficult placements, but they are bloody heavy and the teeth design is not great, they don't bite the ice as well as others. The best teeth design is the new BD express, super aggressive, but if run it to rock in thin ice is game over.