Just my opinions/comments:
Nano Cube, Aquapod, Eclipse Systems
Advantages: self-contained and 'ready to go'; appearance/looks; cost; 'adequate for beginners.
Disadvantages: although adequate for beginners, inadequate without modifications to upgrade your tank to grow with your experience; some individual parts are cheesey; pumps with poor flow, inadequate water turnover; inadequate lighting to support many corals; some have heating issues; modifying the tanks may void the manufacturers warranty; earlier models of the JBJ NC had cracking issues, particular;y the 24G; Eclipse systems are unusually diificult to upgrade the lighting; new reports on AquaPod suggest poor tank lid fitting and cheesey construction
To name a few. SH