Depends on the specific bass amp and what you have upstream to handle the rest of the desired functions provided by the plate amp.
The Servo Plate Amps are Swiss Army Knives containing the following functionality:
- servo feedback loop
- phase control
- Dipole rolloff compensation
- bass boost circuitry
- single cut/boost PEQ
Separate amps usually just provide amplification so the rest, as required, have to be handled elsewhere.