We have two nanos and they are awesome. I highly recommend www.nano-reef.com. That site has tons of information on nano tanks. If you plan on having high light corals check out www.nanotuners.com. They can stuff tons of light into tiny little boxes. Personally I think the NanoCube stand is expensive, especially the twisty one.
The tanks do run hot, but there are several passive chiller options and everyone seems to change the pumps for more flow(personal choice).
One of our nanos(12G nanocube) we run completely stock. It supports a clam, leathers grow like crazy, and oh yeah the seahorses love it. The other tank is an aquapod that I have modded. I added 20 extra watts of light(for a total of 74watts for 12 gallons), a MJ900, custom hood, cooling fans, and soon to be refugium. It is also doing very well.
They are fun, super clean, and who doesn't love a bow front.
Jennifer says you can rearrange them very easily.