I like it quite a lot. I knew about the limited fx peremeters so I use a separate multi fx for compressor, modulation, or slapback.
As far as the amp sounds I think it's awesome. The amps chosen cover alot of ground. For an easy plug and play with headphones or active monitors it doesn't get much more simple.
As for the JCM800 question, it does not have that model. What it does have is a Friedman that sounds eerily close to Eddie's plexi, a great crunchy Marshall-esque amp model. I love that one!