My tropical tank has a sump (well it does when I'm not changing the flooring in the room it's in, it's stripped down right now). Works well. Hides all of the kit nicely.
Problems I've found. The clean up team in tropical aren't as effective at moving things around as the marine version, and plant debris needs to be cleared away. Not a huge issue, but does mean that cleaning is a bit different. The battery powered gravel cleaners can be great for this. Also, marine fish are generally on the large side, and it's amazing what makes in into the sump on a tropical tank that looks like it shouldn't fit. They seem to enjoy the ride as they keep going back in, no matter what you put over the weir. So if you're planning an amazing shoal of small fish, watch how you cover the drains.