For what it's worth, I got 10 SGS and 10 Boge cartos for my eGo, and I really don't notice a huge difference between the two brands.
The SGS ones come individually wrapped and look fairly normal when you pop the soft cap off. The Boge ones aren't wrapped, and have a strange reservoir or something between the soft cap and the atty.
In terms of actual performance, my experience has been dependent on the liquid you use. VaporBomb and Cash liquid seems to work just fine in both, but on the other hand, they seem to be less than awesome with Johnson Creek. (In fairness, the JC liquid I've used is nearly a year old, and is the old "not PG but not really VG" formula)
The biggest benefits for me are not dealing with breaking in an atty, and being able to switch out flavors instantly. Not being stuck ruining a finally-broken-in atty on a flavor I hate is huge. You can get adventurous, and worst case, you're out just over a buck when you pitch the carto that you don't like.
Unfortunately, though, they leak like mad if you don't fill them precisely. And, they "gurgle" more than regular carts do.