Well, there are many benefits to a sump. It can add water volume to your setup, making your tank water more stable. It can be a place to put your heaters, pumps, thermometers, etc. You can also add a refugium to hold micro-algae to help with biological filtration, as well as extra LR
rubble to help keep nitrates down.
It can also hold in-sump skimmers, which can in essence be limitless to how big & how many gallons the skimmer can handle. The bigger the sump, the better. It can be a cheap tank from a yard sale, or a nice acrylic setup... depending on your desire for looks. (acrylic can also be drilled easier, if you want to modify the heck out of it later).
Don't get me wrong... sumps can get expensive if you buy them from a LFS
, but if you're good with your hands and can research them, they can save you tons of money, and will give you more open doors for growth in the future. If you want to add a sump in later, and buy a HOB
skimmer now, you can always just hang the skimmer off of the side of the sump as well... so you're not wasting any money if you add the sump later. So they're not "better" or "worse" but will definately be like adding 4X4 to a truck with a hitch... if you plan to get a boat later... BOOM... you're ready and are prepared. Planning is key (just fyi
, I'm a fan of sumps... as are many people here... in the end, it's up to what you want to do with your tank in the future). HTH