Each piston has it's advantage. Like Tony said the KB107 is lighter. I like light stuff for performance engines. 2 drawbacks with them is because of them being lighter you must have the rotating assy. balanced and their particular about having the ring gap set right. If you don't have enough gap the top ring will butt together and bad things happen. Can't really tell for sure what happened to tomanymopars KB but that may be the case as it looks like there's a chunk above the ring land broke out.
Sealed power pistons are real close to stock piston weight so they don't require re-balancing the assy. They also have coated skirts that supposedly reduce friction during break in. They come in 2 compression levels, the 108's (I think that's the number) are rated at 9 to 1 compression and the 116's are 10 to 1. They don't take any special ring gap so their a slap em in and go.
All in all I usually go for KB's and do what it takes to make them work. I think in the end your ahead.