I want to thank Phil for posting in public forums and interacting with the community with answers to questions. I think it's great.
I'm also going to go out a limb a tiny bit (as I occasionally do) and comment on the target to increase perf by 20% with SP1. If you carefully ready Phil's comment he said we are targeting at least a 20% increase (the key there is the "at least" part). As I've said in the past, I'm not working on SP1 and I don't know how far they will get with perf gains, but I do think that your mileage will vary depending on your hardware and settings... So (and this is where I go out on a limb), if the target is at least 20%, then some will get better than that and possibly a lot better. Of course I'm sure some will get less. I am personally hopeful that I will get more, a lot more.