My dad is looking at getting a bike and was looking at a yz or wr 450. he is about 6'0 210 with out gear. we will be riding mostly trails but the occasional track. But the trails that we ride are pretty rough lots of whoops and rocks. We are leaning towards the yz because it is cheaper at 5300 compared to the wr at 6300. And i have read that it is easier to make a yz into a wr. But it is harder to make a wr into a yz. I was just wondering what you wold buy in our situation.