The 400ex is going to be every bit as reliable as a XR. The 450's are less reliable and require more upkeep.

Unless your doing 60% track and 40% trail I would go with the 400ex. 400ex is super reliable, easy to maintain, and will jump fine. 400ex will have much better trail manors compared to the 450's. And you won't have to change the oil every 2 tanks of gas.

 

I sat on a 450R and a YFZ450 tonight at a dealership. Big difference for the same class of machine.

The Yamaha felt small and cramped. The Honda was only about a inch or two taller but what a difference! The seat is a lot softer and the overall ergos seemed a lot better. These machines are so close in performance that I would probably recommend a 450R for a taller person.

 

I wouldn't get the Raptor 700. My friend just bought one, and three of us (himself included) all think my '05 KFX400 has much better suspension than the Raptor. It's also quite a bit heavier than the KFX, and noticably nose-heavy.
The Raptor owner upgraded from an '03 400EX, and the other guy has an '05 400EX.

I'd recommend a look at the 450 class quads.

Also, if you're looking at track (MX) riding, power isn't all that. A good rider can more than make up for less power over a lesser rider. I smoked the new R700 (stock) with my (stock) KFX.

 

They guy on the raptor must SUCK then. Because I have watched my buddies 2003 400ex with big gun exhaust, jet kit, and K&N put 3 quad lengths on another buddies kfx400. Guy on the 400ex only has 2 months riding experience compared to the kfx guys 10+ years.

The KFX400's are nice quads. But the raptor aren't that bad. They get put down a lot more than they should.

 

There's something seriously wrong with that story. It would take a 400ex with extensive motor mods (big bore, cams, etc.) to beat a mildly modded kfx. Just a pipe and filter on an ex isn't enough for it to beat a stock kfx.

We rarely ever ride on wide open terrain, but we went up a class 6 road the other day. My older brother on his YFZ, me on my Z, and my younger brother on his EX. My youger brother had his pinned, we didn't. He had a hard time staying with us. If we would have all pinned it, the EX would have been way behind. It's really not even a contest. Oh yeah, my younger brother has a white brother's e-series exhaust with a K&N filter, and obviously proper jetting-that's not really a mod but just proper tuning.

But I do agree that he raptor should be smoking the KFX, at least once they get up to speed.

 

depends on the riders

 

That's definetely true. In the case the other guy mentioned, the guy on the kfx had much more experience and was on a faster quad, but still lost.
Between my brothers and I, my younger brother is the more talented rider. On a straight open road, this made no difference. But in the trails he could probably beat us. We've never really raced in the trails, because you can't pass anyway-too narrow.

Another buddy has a bone stock piece of crap 400ex. He also has a little mx track. When he races against other quads at his track, he smokes them like they're not even trying. He raced and beat my brother on his YFZ, and another buddy on a YFZ that has raced quads before and currently races motorcycles.