Also... Lets talk about chain...
From personal experience, in cutting speed (factory sharpened) and durability, my preference goes in this order.
Stihl
Woodland Pro (which I believe is made by Carlton)
Oregon
Whatever came on my Husky from the factory
These are the only ones I have used, so they are the only ones I can speak of. Also, the type of chain should be chosen based on the cutting conditions. Clean wood full chisel, dirty wood semi-chisel. With a 30" bar, I would be using skip chain as well.