The WR 250 and Husky TE 250 both have world enduro titles. All of them are E-start in 2003. Have heard that the KTM is a little porky but what the heck do I know. If I were to buy one here is my preference:
1. TE 2. WR 3. KTM 4. look at 1 through 3 again.
If you want power equal to your KDX with more grunt I would consider the TE 450, KTM 450, Husaberg 400-501, VOR 450?? and WR 450. The 400 class 4-strokes are consistently the fastest times on the world enduro circuit.