The do look nicer, but the SOUND difference is what it's all about...
Here's a mounted comparison. I put my bike back together today, now I'm just waiting on the right-hand pipe from Ducati. I figured I might as well take a couple of pictures for you.
As you can see, the stock cans are FAT like me after a long winter of McDonalds and no exercise! The Termi is a tad longer with the cone at the end, but more streamlined and tucked under the back. The stock cans feel like they weigh at least a couple of pounds more each.
The db killers will come out, I just haven't gotten there yet since I haven't started the bike with the new ECU.