I use a Korg Micro arranger, an Audya 5, and a Yamaha 950. Usually I just use one keyboard, but occasionally I pair two of them up.

Each one has it's strong points and I take the keyboard that is the best fit for the job. I use the Audya if I'm doing lots of salsa and merengue or when a more raw/live sound for other styles such as country and blues/rock. I use the Korg Micro when I need something compact like when I travel abroad, or during the summer months when I don't want to leave my keyboard in the hot car all day-I just bring the KMC into my office, put it under my desk, then when I'm done working it goes with me straight to the gig. The Yamaha is probably the most versatile so that's my first choice on most of my gigs but it's nice to have the variety and freedom to change things up. If I weren't married, I probably have several more keyboards!