Hi,
I use both. MW office is much easier to learn, much convienient user interface. But Genesys has some wizards to design circuits. So you can use these wizards, and can go to MWO to compare the results. Sometimes, Genesys gives wrong results. For example, I designed a filter at center freq. 14 GHz, but in EM simulations, I saw 14.5 GHz, 500 Mhz discrepancy is really much. You have to be carefull when using Genesys.
I think this explanation is enough.
regards,
lkuzu