Eventhough a valid argument is put forth that the arranger is much more suited to spontaneous situations, and I agree, there are many professional gigs that do not require that kind of dexterity. I play arrangers mostly, but have taken my Receptor out too, to take advantage of the superior sounds of my VSTi's.

Now, granted, I choose what I play, and when, but since the open keyboards are much more integrated than a controller keyboard and a Receptor, surely there is a place for them in today's music scene.