Hhaha, you guys and your LPS and Clown FIsh in 3 gallons (minus 1 1/3 gallons for rocks and coral = 1 2/3 gallon).
First off, the Picotope makes no sense when for the same money, you can get the Deco with 2x the lighting and (I believe) 2-3x the GPH.
Second, I can't really think of many fish that will be happy in these. Horses would love the concentration of food, but then you are vaccumming all day.
These tanks are perfect for a few things. In mine I have:
orange snails, nass snails, emerald crab, sexy shrimp, scarlet/blue hermits, zoas, kenya, bumblebee snails, xenia, shrooms, buttons. That is plenty to keep my attention. And there is NO NEED to go overboard and add a fish. Chances are it will go suicidal (clowns like to swim haphazardly and freely), and you will always be cleaning food out of it.
I leave mine over the weekend at work. After 5 weeks, no issues.
Do what you want, but these are not good for fish. Plus, EVERYONE has fish tanks! Corals will be very happy in the pico, fish need more room.
And evaporation is NOT an issue with these if you know what you are doing. If you leave overnight - LID. If you leave for the weekend - LID.
I add 6 oz of R.O. per day and do bi-weekly water changes of 16oz, and mine is thriving. ALl corals have doubled from 6 watts per gallon.
Dont over-think this one.