Bohm and Wersi are both the best and the worst styles on the market, this is because they are programmed for organ play which full arranger styles are not, (Hence the other styles you mention don’t even reach the bottom rung of the ladder if you’re playing organ) however out of arrangers I would put Korg & Ketron on the same level as they just use different types of technology to achieve a live sound, Yamaha is bottom as they need special voices to sound anything decent and fall apart when you try and simplify them.
Casio are fine for the money, while Roland in the G70 era were the top styles available, their lack of commitment to arrangers these days means they fall short, but on the flip side they are great for organ play.

Bill