I have heard great reviews on all of them, i dont have personal experience though. A lot of people like to do "mods" or make adjustments to the tanks such as adding more light, change the filter chambers around, or change the stock pump to improve the tanks. I would recommend going with one. While smaller tanks are harder to take care of in someways such as making sure you keep on your top offs and such, I believe they are easier. ie: your not doing 20 gallon water changes at a time, rather only 1 gallon or so.
Bryan