I would tend to agree with Cueball's post. In more open terrain (aka fast stuff), the Yamaha will shine. The power, the suspension and the handling are all tailored for fast, hard riding. On the tighter, more technical stuff, the KTM will be the star. It truly depends on what kind of riding you do and the type of rider you are. If you ride in tight woods most of the time, odds are, you'll be cussing the blue bike. If you ride MX type stuff, really fast woods riding, or desert, then for sure the Yamaha is a dream machine. In my opinion, the KTM is probably a little more versatile of a trail bike and it won't tire you out as much as the Yamaha. Compared to the Yamaha, the KTM has a very flat power delivery but that electric power works great in the woods and you can ride hard for a long time without wearing yourself out. The electric start is obviously a wonderful convenience too, although I don't agree with all discussion that the Yamaha thumpers are a bear to start. I rode a '99 YZ400 all last year and never had a bit of trouble starting it, hot or cold. Starting is all in the operator. If you attempt to start it like a two-stroke, then you'll have problems but if you do it correctly, starting is a breeze.