I know it has long and detailed tutorials and documentations. So if you have the time it should work well for you.
I've also heard it should produce accurate results for high-Q structures, filters etc.
i am very new to this I was not knowing about wasp-net, I have only worked with sonnet9.53, ADS2004, and micrwave office, all these softwares have demo or trial version and they are also expensive.