I agree with the larger, however, with the larger, as stated, more cost and possible clean up. With that said, you can have more fish or other fish that do require more swimming space. (not to mention the lights)
On another note, with the smaller, less expensive to run, not by much tho, and clean up is quicker and less combersome. JMO
It all depends on what you want and what type of system you want to have.