Outside of a couple of small bugs, the funcionality of stackz is incredible! I have been using lingosoft for 2 years now and I thought it would be hard to replace it but Stackz gives me all the tools I need, like being able to sort based on success, create new lessons with all the individual kanji characters from another lesson, and be able to create new lists from my most difficult words. Congratulations! You created one hell of an app!
I agree, I've been using Stackz 07 RC6 for a while and have no problems to report.