I actually own both bikes(12 wr250r/14 crf250l) and my buddies both have 2013 crf's. I weigh about 185 pounds and the crf does great at least for my weight, but my one buddy that is about 230pounds and it does struggle just a tad bit more speed wise but does fine off road in the same conditions.
Power wise the wr is far superior for sure, the wr can beat it by semi truck lengths in a drag but I do not take my wr offroad at all so I cant compare to much there, however, I do think the suspension stock is going to handle your weight better on the wr, you can just tell spring rate wise on the crf its much softer never mind the lack of adjustability.
I have a buddy that is 250 6'-3" and he rides the crap out of his wr250r and beats it to death and he doesn't bottom it out at all.
Also, I know hard to believe because both seats are not that great, I can ride hours longer on the crf than i can on the wr. The wr literally feels like a brick after just a few minutes.
I still feel like the crf is a heck of a deal and would not hesitate to buy again, its not a power house but for me even though im used to the much faster wr the crf does fantastic in my opinion off/on road. Would I pay an extra $2000 for wr all over again, for me I just don't know? just that much more money that your going to take off road and beat up..for you what you may save up front on the crf you might spend on getting the suspension set up for your weight. The wr can also be lowered by an inch for free, but at 6' you should be fine.