I have attended three MMA matches...a UFC event in Vegas, the one UFC event at Staples and a Pride event in Japan. All were interesting, but in very different ways. In Japan, the crowd was very reverential, knew when to cheer, when to boo...they really knew their stuff. The UFC crowd pretty much was all adrenaline. They wanted knockouts, did not care about the technical elements, etc. It always felt like a fight could break out in the crowd, too.
I cannot claim to be a fan, but, I will say that it's ratings gold for my old network, and for any other TV outlet that airs MMA (Not just UFC). I do find it to be more enjoyable than Boxing, and not quite as barbaric as it used to be/as people perceive it.