They actually are quite a bit different.
Let's see...the SWW is more of an industrial-type material. It's soft, but thicker than the Original. It's a polyster material, where the Original is nylon.
The SWW fits over both prefolds or fitteds. The Original only works with prefolds- it's not cut large enough to cover a fitted diaper.
We used the SWW on our first baby for about a year. We really liked the fit with prefolds. However, I found that after several months of heavy use, they begin to wick. We haven't been using them on our second baby because they don't seem to fit him as well.
I love the Originals for use with trifolded prefolds. This a great combination for under clothes because it's super trim!
I think both are good covers, it just depends upon what you are going to be using them for and how they fit your babe.