Many electric players use effects as powerful sonic tools, chaining pedals or other units together to produce complex, multi-layered sounds, far removed from the clean, dry sound of the electric guitar. Acoustic players tend to be a little more conservative, but integrated multi-FX units have nonetheless found their way into the design of many acoustic guitar amps. The emphasis tends to be on more subtle effects which enhance the acoustic guitar sound - reverb, chorus and delay for instance, rather than the more extreme sounds many electric players use. The priority here is low-noise, high-quality signal processing.
The addition of an FX loop to many amps enables the easy connection of external units such as stomp boxes and rackmount processors. Ideally, each channel should have its own send/return controls for the loop.