My explnantion of Ninjutsu I'll even try to provide videos
I think the biggest misnomer, about ninjitsu, is that it trains you to scale walls, be stealthy, and flamboyant in your fighting. It is, actually, quite the contrary. Ninjitsu, like many MA, is actually a way of life. There are many principles in ninjitsu that are stressed upon for everyday usage, outside of fighting. This is what makes ninjitsu so unique. It is a mixture of reflection, as well as physical conditioning.
Also, we are not as flamboyant as people like to believe. In a good dojo, with a good style, ninjitsu is sort of the copyright-infringer of all the styles. The style itself is supposed to adapt and take the most efficient techniques for their students to learn. For instance, if there is a specific jiu-jitsu technique that is more efficient than the rest, ninjitsu adopts it, and implements it into their style. That being said, MMA-wise, the style is no-where close to anything else. Ninjitsu is meant for real-life situations, so as to get you out of fights before people really get hurt. It is also meant for that sort of self-defense, not against other martial artists, because lets face it, an MA fighter vs an MA fighter comes down to who knows more, and who's better practiced.
In summation, don't knock ninjitsu before the research is done. I for one would highly refer someone to the style, especially those that might not have the muscle-mass or strength for any of the other ones. It is a style that does it's best to cater to those different body-types.
Lastly, most dojos do not spar in class/dojo, but they do encourage the "real-life" practice that sparring entails. As such, the students are encouraged to spar in their own time with each other. And more often than not, it is full contact sparring, because they all believe that you learn nothing when you are pulling your punches.