Ah the learning curve gotta love it. I call it evolution meets the learing curve.
Face it, most of us are very lazy, many of us get real tired of doing maintanence on the tank. Examples:
Crushed coral substrate. Its alot of work to clean, vaccum and all to get the detritus out of the crushed coral. Then someons says sand, ok, so we change the substrate to sand or even bear bottom. No more vaccuming, no more moving rocks, no more up to your elbows in the water. Cool.
Wet/drys.. Used one for a couple of years myself, never had a nitrate problem because I kept after it with maintanence. Most folks however never cleaned the bio balls off every few months, over feed, didn't change the filter floss regularly, the list goes on. Or even if they did clean things regularly they then decide to add a fuge or just go with a plane ole sump.. No more cleaning bio balls, no more wet/dry maintanence, easier to maintain and less work in many cases.
My sump is the old wet/dry, no more bio balls, I do still occationally use filter floss, but alot less hassle, my future plan is to just add a plane open sump/tank that I can reach into without getting cut or stabed by all the little baffles in my old wet/dry and ease of reaching in to maintain the skimmer and pump.
Now if you are just starting the tank then use the wet/dry with bio balls and all, they are a great way to start a tank out, later as the learing curve sets in you may want to remove the bio balls and open it up as a plane ole sump..
You'll learn whats right for you.
There I go getting long winded again.
Thomas