Hypereutectic's don't have the 'toughness' of a forged piston but that does not mean you cannot use power adders. I raced hypers for some time in a 14-15 psi turbo rally engine producing around 1.75 HP per cubic inch... never a single issue. And I have destroyed forged pistons in an N/A engine when the timing got all whacked out. So neither is 'proof' against detonation, just that the forged will more likely survive it than hypers.
So, IMHO, nothing wrong with the KB's. The weight is a lot less (like around 145 grams for piston + pin) so the engine has to be rebalanced, and there is that cost. But that much lighter weight that takes some stress off the rotating assembly. My son and I put a set in his 340..... not a bit worried for hard street use.
BTW.... actual stock 340 compression ratio was around 9.75, not the advertised 10.5; that was only achieved with 'ideal' parts, not the typical factory parts.
