The 190A8 climb rate isn't so dismal as you may think. It's simply "average"...
You can't compare it to spits and 109K4s that almost peg 5000fpm climb rates.
Compared to the japaneses planeset, the non-spit brit planeset, compared to almost all US planes, it is "average" in climb with WEP, but keep in mind it has 10 minutes of solid WEP to use. It won't totally out-climb something from a dead heat, but if it's chasing something, they also can't get away too easily, either.
It's a great offensive platform. You keep in the mindset of "how it can attack something else" and it's pretty good. You start thinking "how it can/cannot evade something attacking it" and folks seem to fixate on the large turn radius.