This is probably the best roleplaying system ever devised. We have been playing the 2ed and 3ed for 5 years now, playing d&d before that for at least 10.
Even though the book focuses on anime, the rules themselves can be applied to anything. We do not play anime themed campaigns, instead we at first used it to run a typical D&D 3.5ed campaign. Except the focus got removed from killing things and taking their stuff into actual heroics and character development. What it should have been about all along.
Only thing you should avoid in this system is the dynamic powers attribute, it has been planted there as a "catch all" exception handler, and it is seriously not necessary. Power flux does the job just as well.
My group became very evangelical about this rules system, and we converted quite a few other gaming groups to it, once they gotten over the "I am not being railroaded" shock.
Simply said, new players try to look at attributes, then make their character after them (as they used to do in D&D, by picking a class, then tailoring a personality to fit that class), while in BESM you first make a personality, and then it is a simple measure of picking attributes to go with it.
The game avoids numerous issues in other roleplaying systems, and doesn't introduce any issues of its own, except perhaps the need for someone to guide you through the book initially (depending on how quick you are to figure things out). The system looks very daunting at first glance, but once you get the basics down, it is the easiest system ever to work with.
I am almost always a DM, and no other system ever let me create opponents as unique and interesting as this. Players claim the same for their character concepts, you are absolutely not limited by anything but your imagination. Also, characters do not grow as "tall, thin pillars" as they do in systems like D&D, instead they become more and more versatile, which avoid the horror of having each character play its own small part, while others wait, that is so common in D&D and similar systems.
All in all, get this, and play any campaign of any style you can possibly imagine.
[5 of 5 Stars!]