XFdtd,HFSS,uWave Wizard - comparison

I need to simulate standing and propagating waves in a waveguide containing antennas (transmitting and receiving). I would like to know which software is the best for it - XFdtd, HFSS, uWave Wizard or something else. With XFdtd I can use a GPU accelerator which makes it much faster. Can anyone comment?

i think it depend on the size you need to simulate

HFSS is based on finite element method, it is accurate full-wave numerical method, therefor it is reliable and we can get many application examples online.

xfdtd is also popular based on fdtd. the GPU acceleration is promising feature i think. but for small size problems, i doubt if it is necessary.

i don't know uWave. sorry about that.