I myself like the PICO sized tanks.....I have a bunch of them all around the house from 1 quart to 2 gal in size. ***** had a closeout on some very nice betta tanks. One was a basic all glass tank rectangular in shape, but the other was a rounded corner 1 1/2 gal tank of all glass construction, They both came with a small hob powerfilter, and a clip on light, which for the ost part is useless for a reef or corals, but suitable for a small fuge. They originally sold for like $19.xx and $23.xx but clearanced priced at $3.00 and $6.11....hard to beat those prices and they make great pico tanks.
I turned one of the rectangular tanks into a mini sump for a 2.2 gal Red Sea Wave tank, and another I have as a fuge for the rounded corner tank.......
One thing, is those small 7 watt non controllable heaters......Keep a very close eye on them as they can heat your tank up fairoly quickly if you have a light over them, which is also going to heat the water..They are designed to heat the water just a few degrees above "whatever" the room temp is, so if your lights heat the water to say 80 deg, the heater is gonna run it up to 83 or 84or maybe more, since it doe snot know water temp from room temp. I had problems with them intially but my cure was to utilize lights during the day to keep water warm, and since all are on timers, when the lights go out the heater comes on later during the night, so my water has been staying within 2 deg which is not bad considering such a small volume of water is in use.. Walmart has the round 7 watt heaters for under $5.00, and other than shape fromn a round tube to a flat mat, its the same as the hydor mat 7 watt heaters are and just as functional, but the cords are kind of heavy duty and stiff, where the hydor is like lamp cord and very flexible....
The 7 watt and 13 watt Art Deco PC lights work very well on these sized tanks. Deco Art is made by Red Sea and they can be found very cheap. You can get different bulbs for them quite easy and cheap from 50/50's to full actinic to daylights of various temps.
PICO' tanks ya just gotta love em so much stuff n such a small package. My main lfs hates them as they say they are so hard to take care of, but I find them quite easy to manage. We used to have night lights here and there in the house, now we utilize those pico's for night lights.