Palmer PDI-09 vs. H&K Red Box Classic vs. Behringer GI100

[Timon]

I play a Sansamp PSA 1.1 through a Palmer PDI-09 speaker simulation into a Tascam US-122 and my PC. I'm pretty pleased with it. (still need an EQ though, see my other topic to help me there)
I now wanted to add a Hughes & Kettner Red Box Classic speaker simulation to the other output but the sound is really harsh, is that normal or am I doing something wrong? If that's what it sounds like I'm surely gonna return it.
What about the Behringer GI100, is it a better alternative?

[Timon]

Does nobody use one of those things?
I especially would like to hear about the Behringer since I'm thinking about adding that to the other output to run together with my Palmer... but I don't wanna get it if it's way worse than the Palmer.