When looking at what makes for a good or bad sump, or if one is better than the other, then you must first think about what a sump does. I would submit that a sump serves three purposes; space to hide your equipment, a way to dial in top-off, and to add water volume.
1) Space to hide your equipment: this one is very cut and dry. It's hard to put a skimmer, heaters, etc. into a display tank, which is why we use sumps. Even if you could fit them all in, they're an eye-sore. As long as the sump accommodates the filtration equipment that you plan to use, plus some extra room for a little expansion in the future (always going to want to try new toys), then this requirement is met. Even if there is no room for expansion, at bare minimum, it must accommodate what you're planning on currently using.
2) Top-Off: That return pump chamber is vital. It isolates where evaporation is expressed, and allows you to maintain a constant level in the equipment part of your sump. This allows you to dial in your equipment to run more efficiently with stable conditions, whether it be a constant water height for your skimmer, constant water height for your reactor to maintain the same flow rate, etc. As the water level in the return pump chamber fluctuates based off of your top-off system, it has no effect on any other part of your tank, and it's important to isolate the fluctuation there.
3) Water Volume: Years ago when I was just getting into corals seriously, I went to a fellow reefer here in Houston that at one point, was world renowned. He left the hobby years ago but will be coming back soon, based off of what he has been saying recently. I was telling him (Dennis, aka d2mini for the older reefers) that I had a 40 breeder and I was struggling to keep things alive, let alone thrive. Keep in mind, when Ecotech first launched the Radions, they used his 135 gallon cube tank as the poster child for their advertising. His advice to me was that he himself had never been successful until he got north of 100 gallons, and that if I could make it work in my 40 breeder, then there's no tank I couldn't make thrive. I eventually was able to dial in a smaller tank like a 40 breeder, and once I upgraded, the rest was much easier.
I said that to say this: you need to have a chamber in your sump that fills almost to the top of the sump, circulates water into the main system, and adds water volume. It makes everything easier. My personal goal on this is roughly 20% of your water volume being in a chamber with maybe live rock, but no lights, frags, or anything else. It exists simply to hold water. This will make your life so much easier no matter what you're trying to accomplish. Everything moves slower with larger water volumes, which means everything is more stable.
For my current fish room expansion, I'm probably going to buy two tall, thin water vats (don't want to take up too much real estate) that will plug into my two reef systems. Water goes in, water goes out with each their own pump that pushes water in and plumbing flow back into the sump. Whenever it's time to do a manual water change, just turn off the pump pushing water in, drain the chamber, fill it back up, then turn back on the pump. Very simple.
Here's my personal sump design that I use that enforces the three principles described above. This is the exact model I use on both systems. It holds roughly 20% of total water volume of each system, with both sumps varying in size. This drawing is based off of a 20 long that was converted to a sump, which is what my secondary (smaller) system is using. The return pump should be oversized, and regulated with gate valve 1. Gate valve 2 controls the flow through the added water volume chamber. The flow through the water volume chamber doesn't need to be a whole lot, just enough to keep it circulated. You could even throw a dedicated pump in their to eliminate dead spots, or use it as a place to pool detritus that you can easily syphon out.
.
