A Raptor 700 is a sport quad. Its not one meant for racing as the 450cc quads are but its very much a sport quad. The bigger engine I think would be better for trail riding and on the dunes as well. Its a little bigger quad so you being 6'3" would appreciate that. I would assume it wouldn't be as hard to stall out. The clutches on the 450 machines are pretty touchy.

 

Most quads are 4 strokes, not 2. There hasn't even been a 2 stroke sold new since 2005. I prefer the 1 hour top end on my 250r 2 stroke vs the half day affair to change out the YFZ...

450 quads can be ridden slow although it takes a bit of skill. since you are new, something a little less hyper like a 400 class or even the 700 raptor will suit you better initially. These machines tend to have a softer, more comfortable suspension and seating position. They will handle well and are good choices for a fill day of riding.

In the dunes, power rules. Power to weight ratio is the absolute king to get that machine moving and up on top of the sand. Sports are inherently lighter, and with good sand tires you can go just about anywhere, whip the back end out, carve a dune face, getsome air time. It really is something to be experienced. You just don't see a lot of utes in the dunes and for good reason.

 

Would the raptor 700r be the better choice for me?

There's an ATV park near me which has miles of trail riding and dunes. And I mainly wanted the 450r because it had a lot of acceleration.

 

See if you can take a ride on both. Never been on the Raptor but it's no slouch. Yamaha has won a lot of endurance races like the Dakar with the Raptor.

 

The Raptor is going to be a little more user friendly until you get used to riding. The 700 is a touch faster than most stock 450s. They are a great trail machine with plenty of power for the dunes. Better for you? There is no way I can make that call, but it is better for a lot of riders.

 

I'm 6'3" and a Z400 fits me fine. So does a 250 moto 4.

 

The problem with all chain drives is the ground clearance is lucky to be 3" to 4" below the rear sprocket and ground.
Utilities are not slow. A 500 4x4 Outlander would dust a 400ex .

 

From the sound of your post, my guess is you don't have much riding experience. I would recommend trying some quads out if you can find someone to let you ride some. Without experience I don't think your going to find someone that has a hot two stroke machine let you just take it for a spin, unfortunately in my 65 years I have saw many inexperienced people jump on fast machines and wrap themselves around a tree. Honestly about 10 yrs back a friend of my son wanted a faster machine so he bought a 400ex but had no prior experience in riding fast. Within the first two hours of ownership he wrapped it around a tree and broke his back. He now rides a small 250 utility machine not much faster than 25mph. Not trying to badmouth here just don't want another statistic added to us atv/utv owners.
Do your self a big favor and do a little riding on various machines and see what YOU really like.

 

Since this thread is a bit old, i would be interested if the op has made a purchase?

 

I went riding at a park relatively close to me today Coyote ATV Trails - Illinois Motorcycle and ATV Trails. With all the turns and steep hills, I think the top speed I was able to muster on the trails was about 30 mph. Most of the time, about 20-25 mph was about average speed. Some of the hills had a pretty steep dropoff. Hitting them too fast could easily get you some unwanted air and result in a nasty crash. But it was nice to have plenty of reserve power on tap. I could easily power up any hill they had even if I had to let up at the top. Then the engine braking kicks in and I can maintain a safe speed going down too. Its a pretty nice place to ride just not that many miles of trails. But its the closest park to me, about 60 miles away. The main trail isn't too difficult, its the side trails that can get pretty dicey. I helped extract a RZR 1000 XP that had ventured off on one of the side trails and couldn't make it up a muddy hillclimb to get back on the main trail. Good thing he had a winch but the cable kept getting bound up. I actually hooked the cable to my BF and helped him freespool it by pulling on it, couldnt get it to freespool by hand. Once we got the cable unstuck, it did pull it out and up the hill, i was impressed.