I think a beginner would be more comfortable on the KFX 700. The things I would be looking at if I was a beginner are the fact that it is an automatic transmission quad, so you don't have to always worry about being in the right gear while riding, so you can spend more time learning about controlling the quad on hills and paying more attention to where you're going. Also the KFX 700 isn't as prone to wheelies as the Raptor, which is a big plus when trying to learn how to climb steep hills. ANother thing to consider is the 700 has more ground clearance in the rear because of the shaft drive, and shaft drive means not having to worry about adjusting, cleaning, lubing, or replacing a chain and sprockets as part of regular maintenance. As for which is faster stock, I've personally watched several showroom stock KFX700's race stock Raptors and win, and race Raptors that had full exhaust systems, air filters etc in the dunes and keep up fine.
If the new rider wanted a sportquad with reverse and a manual transmission, I would highly recommend looking at the Z400 or one of it's clones, instead of the Raptor, simply because I don't feel a manual trans bigbore quad would be a good choice for a beginner, too much power and too easy to get in over your head while learning. The Z400 has more than enough power for most beginners stock, and can be modified to run almost as fast as any other 4 stroke quad out, or traded in on a bigger quad later after the rider gains enough experience to handle it. Another plus to the Z400 for somebody new to atv's is the fact that it's less expensive, why spend more money for your first quad than you absolutely have to, when you don't even know if you're going to enjoy riding quads.
I know people that went out and bought expensive first quads, only to decide they didn't like them and lost money when they traded it in on a dirt bike that they felt more comfortable on the trails with. Either way it's your money and ultimately your choice, so think hard about what you want to do and what features are real world important to you. This is my honest opinion about this, and I would tell anybody in my family the same thing, even though I am a Honda rider and ride a 250R, I would still recommend the Z400 or KFX 700 to new riders looking for reverse, if reverse didn't matter, the 400ex would also be at the top of my list for a new rider. Good Luck.