I also tried converting SISS (Giga) in Kontakt 2.02 and there are many problems.First of all, I'm getting consistent crashes with the cellos. About midway through the conversion both Kontakt and DP just quit and there are no error messages. I've also tried just using the standalone version of K2- crashes everytime.

Secondly,I also have Gigastudio 3.0 on a PC laptop and did a comparison between the native Giga format on my PC and the K2 conversion on my Mac.
What a difference!! The K2.02 version is way off. The pizzicato violins just cut off abruptly in K2 and in Gigastudio it sounds great- nice smooth releases.I never realized how much difference there is between the K2 conversion of Giga, and Gigastudio playing this library natively.Unfortunately, It looks like there are still many issues to be resolved in K2 regarding the Giga conversions.I would love to hear from other SISS users.