Aggressive riding and China-bikes are mutually exclusive things.
I've had 2 of em and both of them are terrible for anything other than put putting around smooth trails. I ended up getting a brand new wr250r. I've been able to keep up with my buddy's yz450f right out of the box, well, keeping him in my sight anyway. My China-bike wasn't even close to being able to do that even after modding everything I could.
xt250, wr250, crf250 are all solid options for true dual sporting.
So far I have changed gearing to 14/51 from the stock 13/43 because I do almost no street riding and zero highway, got some aggressive tires, a skid plate, hand guards, and I'm getting the rear shock re-valved for my weight. But even stock this thing is way better than I am. The only thing I had an issue with stock was this massive sand hill the 450 struggled up. I only got halfway before I ran out of power (highway gearing) and tire (50/50 tires) now the only thing stopping me is my skill level.
