In simulation on power amplifier, HB is more powerful than PSS method......The disadvantage of pss is the low speed and "fragile" convergence...
The PSS is also believable if your simulation steps is correct enough.(e.g. the order of your highest harmonics)..........of course, The precondition is, there is no divergence.......
The difference between HB & PSS is trivial, since the error of transistor model is more notable, especially in large-signal region......