My son has a 2000 KX250 and it has more bottom end than my 2001 CR250. But the CR of that year is known to be pipey! He's got a 12 or 14 oz flywheel weight to help smooth out the power hit and I have a 10 oz on mine. I wish mine weighed more. We both have gnarly pipes too which helps bottom end. One of the things that helped my CR was jetting. That made it much more "happy". :laugh: Here's the deal: The KX weighs about 8 pounds or so more than the CR. The KX feels much more heavier to me because the frame is steel and I think the weight of the bike is higher in the frame. The CR is of course an aluminum frame. Most 4 strokes will weigh in even heavier than the KX or CR by a few pounds. Add a starter and you'll add another 15 lbs. or so. While I have not ridden a CRF250, I have ridden a CRF230. The 230 is a great trail bike and that is it. It basically won't wheelie. :( The YZF250 I rode felt almost more pipey than my CR with the flywheel weight... and it's a 4 stroke. Personally, I do not like revving 4 strokes to the moon which is what you basically have to do with the new breed of 250's... barring maybe the CRF250 which someone spoke about above.
Now, to contradict almost everything I wrote above, I rode a 2006 YZF450 and I have to admit it felt light (aluminum frame again) and had plenty of low end. Which is why if I bought a new 4 stroke it would be a 450.... furthermore, it had much more low end than the CRF450 that I had ridden previously.
So what am I saying? If you hate the bike and have the money get something else. Try to ride it before you buy it. Looks and showroom feel can be deceiving. If you are short on funds, spend a few hundred bucks on the KX and few hours jetting. You will be surprised how the bike will respond to the right jetting..... even a turn of the air screw makes a big difference. What am I leaning toward for my next bike? I'm really not sure, I do not want to kick start a 4 stroke and do not want the weight of a starter. I do not like constantly having to adjust valves, and hate a noisy "mechanical sound" motor. I will probably strongly consider a KTM300 2 stroke (however, I have not ridden one yet) or a newer CR. 2 strokes are easy to rebuild, kick start, have fewer moving parts and when jetted correctly, they can be just about as torquey as the new breed of 4 strokes. :ride: