The 300 will take the 250 in a drag. The benefit of having an automatic is hillclimbing the knarly stuff. I had a 300 before my 400ex and I could never put it or the 400 in the same places as the 200 or the 250. The clutch hurts when you need to bounce over ledges going up the hill. As far as frames the 250 has a taller seat hieght than the 300ex.

 

The 300ex will take the 250ex anywhere. I'm not bashing the 250ex because I think it is a great quad. Personally, I would rather have a manual ATV for hill climbing rather than an automatic clutch. You don't have to let off te throttle to change gears. Its a whole lot quicker to pull the clutch and change gears than to let off the gas nd change gears. You'll lose too much speed if you have to let off the throttle.

 

Around here when we hill climb we get a running shoot in 3rd then downshift to 2nd and pinned from there. If your doing hillclimbs and upshifting its not much of a hill. The hills around here you can't walk up if there aren't any trees to grab hold of so they are very hard to make up. The only reason a clutch is good is so if its starts bogging you can just work it and hold that gear longer. On an auto clutch wheeler you'd have to downshift. Both manual and auto have there goods and bads on hill climbs.

 

If your that bent on beating a 250EX, your best bet would be to sell the SX and buy a 250EX. Then if you still want to go faster, White Bros. makes a pipe for the EX, and the engine is alot more modifiable (cam, hi-comp piston, air filter). Works also has shocks out for the EX now too.