If you prefer to play with other musicians, then you can do just that. Just switch into full keyboard mode, turn off any backings, choose your favourite piano voice and away you go - a 76-note board obviously preferred. Then, when you feel like it, play around in full arranger mode. Choices, indeed. That's why I'd rather have an arranger, I can play what I like when I like. And, as DannyUK says, it's about having fun.