It's kind of hard to review a business where the quality of its service/product is really merely a reflection of your interest/performance. So let's put it this way: If you want to be challenged to an extreme degree both physically and mentally, Krav Maga is the discipline for you, and Las Vegas Krav Maga is a great place in which to explore it. I only went two times, but both times the instructor (in this case, DC Pacheco) and the students were welcoming, helpful and never created an air of intimidation for the newcomer such as me. The pricing is a bit steep ($99/month if you lock into a multi-year contract, otherwise as much as $150/month), but you can come to as many classes as you want, ranging from the Krav Maga basics to full-on sparring and more fitness-oriented offerings.
But prepare to be humbled. I sure was. :)