I use the new E3 plugs. They centralize the burn in the cylinder without me having to worry about degreeing the standard style of plug. They do burn a bit hotter than the like heat range of standard style plug, but nothing a little bit richer fuel mix can't take care of. AND then there is the $6 apiece price factor, but those are the only two "downs" I can think of.
Plug degreeing is where you turn the open end of the plug gap down toward the center of the top of the piston "where the plug comes into the cylinder on a slight angle"... Degreeing does no real good where your plug comes in through the dead top center of the cylinder, which is another reason why the E3's are so nice.
Anyone who has ever run a saw with a degreed plug "where it can be degreed" knows what I'm talking about as far as how much better they run and respond
Now as far as regular plugs goes... Personally don't like Champion and haven't had too much longevity luck out of the NGK's. SO I preferred using the Bosch's "degreed" until I started using the E3's.... Now I don't have to worry about using degreeing washers or anything, just throw in the new plug and do a quick tune up...
Just my opinion on the subject....
Greg