A newer 2 stroke 250 can lug you around the trails just fine without fouling plugs. If you do not get an enduro version of the 4 stroke, you can easily overheat the stroker if you trail ride. If you buy a used 4 stroke (especially a 250), just be careful, most say they are ticking time bombs. And if you blow that motor up, you will have more in rebuilding than the bike is worth (in some cases). If you're not tapping out your 2 stroke all the time, you will not need to redo top end every year. I used to ride mine quite a bit, and only did the top end about every 2 years. 2 stroke all the way. And they are a lot more mellow than they used to be. You can go as slow as you want, and keep the RPM's as low as you want. I may possibly sell my YZ250 if the price was right.