While I agree with most of it I have to disagree about Yamaha as I have always rated them as the bottom of the pile when it comes to styles, the main reason is that many of them use specially created voices (Megavoices etc.) to make them which makes them difficult to edit, they are also more song specific which soon becomes very boring and canned, the final problem is because they are designed as an entity, if you try and simplify them too much the style completely falls apart. (While the sounds and drums have come on in leaps and bounds the style makeup still doesn’t sound anything like a real band)
Korg have always been busy as their arrangers came from their professional arm (Hence the reason they were a pain to setup and use in the early days) rather than the home hobby market of all the rest, however if you leave the styles off it is one of the best arrangers out there to play in a live band due to the fact it sounds live, unfortunately their Workstations sound even better and are even more flexible so the Arrangers just stay primarily in the home hobby market.
Roland had some of the best styles and sounds in the G70 era (Nothing else could touch them) as they sounded exactly like a real band (Compared them many times) plus you could edit or simplify them and they still sounded real.
If you want simple styles you need the type that come with entertainment organs, as they are designed to allow the player great flexibility (They have 2 keyboards and pedals on the go) in playing without the style getting in the way or falling apart.

Bill