The demo version will suddenly cut the audio for 5 seconds, and then you can keep playing. With BIAS Amp II you can control every single aspect of the amp It does offer the usual parameters on the front like Gain, Volume, EQ, etc., but where this plugin really shines is in allowing you to switch the actual componets of the amp, likes tubes, controling the preamp, poweramp, cabinet, mic positioning, etc., to be able to tailor the sound to your needs.
If you’re the kind of person who likes getting into the nitty gritty of amp design, then this is definitely the plugin for you.