Then you are doing something wrong with that powered speaker...a 65 watt Peavey Bandit can keep up with all but the loudest metal bands.I don't have a lot of experience with solid state past my first Laney amp back in high school.
I recently tried an emulator pedal through a 500 watt powered QSC K series speaker. Sounded like 5 watts when in the practice space with the band.
The challenge with solid state is getting a good loud sound.
You would probably need 2000 Watts for useful emulation with a loud band.