coaxial cavity filter, model in cst

hi! everybody,
I have cst and hfss.I want to design a microwave cavity filter,but I don't know which is better,cst or hfss?who can give me some suggest

I worked with HFSS and CST.
And I had many problem's with CST and solve them only after much addition mesh cells.
I think that in CST is not very good automeshing.
Many problem your need to solve by hands and head .
For large devices, with not very complicated structure, CST works good.
But if you have large difference between elements dimensions and your device also very resonance structure (for example coaxial cavity filter), you must make mesh refinement by hands and you have huge size mesh cells.
In HFSS the mesh's refinement is the better And for resonance devices I had more good results.

I use CST to simulate the cavity filter
it is well for filter design, and convient to drawing!