Well to answer your question, not only do i like 2 strokes because they are pretty cheap to fix (a whole topend for my yz with piston and rings is around 150), i think they are a blast to ride. The reason im not really suggesting a four stroke, especially a race bike is because right now, that is what all the motoxers use so they are high priority. They are holding their value really well and take a lot to fix the top end. I dont know exactly about how much redoing a 4stroke motor is but it will be in the grand area if you chop a valve or something. I use my yz125 in the woods and have no problems with a stock sprocket and no flywheel weight. Sure you gotta be on the pipe for a motocross bike, but theres really no other feeling like throwin up 4th gear roost when you hit the powerband. I honestly think the 200 EXC would be the best for you. Its got good low end, so you wont stall it in trails often, but it still has the top end powerband hit that 2strokes are known for. Sure the kdxs are cheaper, but i feel like they are less powerful and fun than the ktm 200s. KTM and gas-gas are basicly the only company that still produce great trail 2strokes. The wr250f is good on trails too, but really id pick a 2stroke over it. What you really got to do to decide wether you want a 2st or 4st is go and ride them. Also about the yz250, it will manhandle you until you know how to ride it, but once you get the hang of it (like 2 weeks most) than you will rip. Many people love their yz250s in trails with a flywheel weight. Sorry about the rambling i hope you can follow. My bottom line is get the KTM 200EXC and i guarantee that you will love it.