ive had 3 nanos so far. they aren't too bad if you keep up on water changes. adding chemicals (which at this size is a must!) comes to be little difficult but with some math and a syringe it can be done.
my first 2 were LPS and zoos and my last one was SPS, LPS, and zoos. i combined them all into one 30 gallon and i find that it is harder to keep up with the 30 than all the others.