CRF valve problem, good trail bike?

Ok, so i want to upgrade to a new bike. i reeeeeaally want a 300 xc-w or exc, but they are kind of expensive. a klx 300 or wr 250 would be ok, but iv always had hondas. I know that crf's are great trail bikes, but i have heard that the valves, like most racing bikes, have to be rebuilt often. What year did honda fix the valve problem, if they have at all? thoughts on anything?