Seeing as nobody else has done so, then I will reply (also, I'm 'local'). Mind you, this might not help much.
I regularly use Comp 3, they're excellent for muddy, greasy, slippy going, but wear out quite fast. They probably wouldn't last any time at all on tarmac.
It might be the case that 19" Comp 4 are the same as 18" Comp 3?
Second that. Comp 3's came stock on my husky. They were as good as s12's! For all of 100 miles that is :(. Then they were junk. In fact the comp 3 front was junk even when it was brand new. They may be better than other road legals though...
Mental note: uncheck "show signature" before submitting next time :