I started a 10 gal SW about a year ago, and it was easily one of the most rewarding things I have ever done. It took about a month for the live rock to cycle the tank, and then about another two weeks or so to have a cleanup crew rid the tank of garbage. That was when I got my first fish. I thought that salt water fish were the pot of gold at the end of the rainbow, but I don't even look at the fish anymore. Why look at fish when you can gaze into the depths and watch the ten trillion random creatures in the live rock do their thing?
I have a great LFS called The Aquatic Critter in Nashville, TN which has the most hitchhikers per square inch that I have ever seen. Just last weekend I bought two pieces of live rock, one that has two massive pieces of brain coral, and one that has some other kind of polypy-zooanthidy-looking hard coral with weird tentacles coming out of it.
I am willing to bet that oceanographers don't even have names for 90% of the crap that comes on live rock or falls out of it. So I guess what I am saying (in this ridiculously long rant) is that you should go for it. It is a joy for me to keep my nano running great, and honestly, I have more problems out of my FW tanks.
I'll put it to you this way- My TV sits on top of my entertainment center; my nano sits IN the entertainment center.