To whomever asked it, my exchange program was funded by a grant from two foundations, set up for the express purpose of allowing military officers and cadets/midshipmen the chance to study abroad. I did the program right after I graduated from college and before I went to TBS. A wonderful opportunity, to say the least.
Roppongi is like anything or anywhere else: It's what you make of it. If you want to go to dirty, nasty places, you're going to meet dirty, nasty people and probably do dirty, nasty things. Hey, that appeals to everyone at one point or another. You can hang out with Japanese people, you can hang out with gaijin, or you could--gasp!--hang out with all sorts of people. The way I see it, Japan isn't the easiest place for a non-Japanese person to be, simply because the population is over 99% ethnic Japanese. I'm not trying to knock either the Japanese hospitality or the foreigners who visit, but it is a simple fact that if you have not spent at least a little time getting to know the people and the culture, you might miss out on some things.
Roppongi was a BLAST each time I visited, but I had some...interesting guides. And it definitely wasn't my favorite place in Japan. If you want to blow lots of money and have a kick-as$ time, sure, live it up! But there's far, far, FAR more to see in Japan than the toilet you're yakking in.
Personally, I'm a fan of Kyoto, Nikko, and Etajima. But that's me, and time strange sometimes. Time for duty....@#$%