Another point to consider: speed is great, but just make sure you're not hurting yourself! Once you find a technique that feels comfortable, you'll still need to remember to take breaks now and then.
I type for a living, and when I'm not typing I'm knitting, so I need to be very careful about repetitive stress injuries.
If something starts to hurt, stop what you're doing and rest. Better to take a breather now than to be forced to stop knitting forever.