The only downsides are that they are heavy and not well insulated. A heavy tank can be difficult to move and once it's set up with the dragon inside, you'll not be inclined to move it.
[header] How to set up a tank for bearded dragons [title] Choose a glass aquarium. [step] This is the most common type of tank for bearded dragons. Glass aquariums are inexpensive and easy to find at local pet stores or on local market sites like craigslist.