what do you think about Hspice for RF design?

some people tell me Hspice is not good for RF design ,why? I hear that the Hspice2004 support RF design, right?

Cadence SpectreRF and Agilent ADS are powerful for RF circuits design.

Because it lacks for display function like NF, IIP3 and 1dB point, another fatal problem is that it can't show data on smith map. You still can write your own equations to compute these parameters but its not intuitive.

For linearity analysis, most people use FFT to calculate the 3rd order or 2nd order IM term. But it needs a long time to do a transient analysis, this brings more difficulty to optimize your circuit. And the 3rd order term is always so small that the arithmetic noise caused by transient and FFT calculation will probably affects the accuracy of this small term.