I wouldn't go as far as saying it has nothing to do with it. There are pro's and con's with both designs.
It's sort of like saying there's no difference between 4 and 8 cylinder engine's. Sure design can help a 4 cylinder Lotus run as fast or faster than an 8 cylinder Mustang. Like wise they've come a long way in designing some of the newer 8 cylinder engines to run as efficiently or even more efficiently than many 4 cylinder cars on the road today.
But the fact remains, it's easier to make power with 8 cylinders, and easier to be efficient with 4.
Take a sub box, it is easier to get more volume with less power if your box is ported. Conversely it's easier to get tighter bass out of a sealed box. Putting money into the parts and the design will even these traits out similar to engine performance. So if you're willing to pay a lot on your sub then it probably won't matter.
But if you're on a budget and can't sink very much money into your bass and are looking for a musical sub I'd suggest looking at sealed designs. If you're more about huge explosions shaking the couch during a movie then a ported sub will most likely do the job better.
This at least has been what I've experienced with low priced subwoofers. Like I've mentioned in the past, before I discovered Axiom, I considered $1000 as an extreme amount to spend on a single sub unit. Most of the equipment I'd ever had/heard before that was in the $250 - $500 dollar range.
But I have to say, spending $500 dollars with an internet company like Elemental Design's, SVS or HSU will get you 2 to 3 times the performance than you could ever get spending the same money at a big box store.
