aio vs sump

Just signed a lease and verified my apartments maximum tank size permitted. The maximum size they allow is 55 gallons. I also verified a while back that my renters insurance provider would cover tank leaks or any water damage for that matter. At this tank size, is the benefit of a sump vs AIO...

Looking to buy a saltwater tank. Not finding much information on them. I love the dimensions of the 48 Gallon Shallow Ext. (30" x 24" x 15.75") I had a small biocube 14 AIO a few years back but, this would be my first Sump. The fiji cube's don't come with completed plumbing. What is the...