Actually I find that arrangers are the most versatile keyboards of just about any. It's also what a lot of people own as their first keyboard. Better quality arrangers not have the basic keyboard sounds but can "jam" with you without you having to pre-program (ie: sequence) the song. They are at home in solo or ensemble use and their learning curve is often less than what professional workstations demand. That's why we all own one, or more.
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Jim Eshleman