The SR-16 is one of the most popular drum machines. As a stand-alone device, it is somewhat limited in the pattern of drum beats it can do. You often see units like this being used by duos, but the sound is often boring with little variation in the drum beats (possibly a flashy intro and ending, but not much more).
We use the SR-16 for the drum sounds. There is a big selection of snare, bass, tom-tom and other percussion instruments, all of which are triggered by the XP-80. The flexibility of the XP-80 enables us to get very realistic drum backing.
As an independent device, we hook it up to its own amplifier with a 15" speaker to produce a floor level bass sound. It is also connected into the PA to project the cymbals etc.
Unlike the average drummer, Al doesn't lose time, fall off his stool, break the bass pedal, get drunk, get drugged, not turn up at all and we always have a spare just in case....