I would normally expect to see a comparison between Java and C#, or between Java and Zonnon, which is not to say that there is no reason to compare the two you mention.
It really depends on what you want.
Platform independence? Logic-oriented object model? Operating environment controls (less crashes)? I would say Zonnon.
Massive peer support? Business-oriented object model? Tight integration with MS Windows? I would say C#.
Platform independence? Massive peer support? Practical object model? I would say Java.