Krav Maga in Phoenix

a krav maga school opened in my area (chandler) and it caught my interest.

http://www.reactdefense.com/krav.cfm

"Krav Maga (Contact Combat) is the official system of defensive tactics, hand-to-hand combat and self-defense employed by the Israeli defense and security forces, the Israeli national and military police, and its special operations and anti-terrorist units."

is krav maga realistic or a bunch of bullshit? what are the classes like, i come from a bjj and muay thai background.

the instructors are Jay Ackerman and Cris Moosman, can anyone share any information about them?