Having owned Roland, Korg, Yamaha, and a few other brands, I can unequivocally state that the user/owner manuals for each and every one of them were poorly written. Not one manual, including the one that came my current keyboard, seems to have been written by a competent user. Instead, I believe they were assembled prior to the keyboard's release, placed in a Zip-Loc plastic bag, sealed and never looked at by anyone at the factory level again.
Fortunately, there are websites such as the Synthzone and PSR-Tutorial that tend to have a lot of very helpful individuals frequenting their forums, folks that have a significant amount of technical expertise, plus a lot of hands-on knowledge with the various brands and models. Not only does this save many new or inexperienced players a lot of time and effort by answering many of the technical questions that are NOT well covered in the manuals, but additionally, these same individuals usually take the time to provide step-by-step instructions on how to go about solving a particular problem. While this is not always the case on this particular site, without a doubt it IS the case at PSR-Tutorial, both on their forum and a number of other pages within the site itself.
As DonM said, the operating systems of each major brand has some great features, and each has their downsides as well. Personally, I've never really had a problem learning any of the operating systems, but without a doubt I can state that it takes years to learn every nook and cranny of any MOTL and TOTL arranger keyboard's operating system. And, just about the time you think you have an OS mastered is when the manufacturer makes dramatic changes to some of the more important features that you frequently use as a live entertainer.
Of all the operating systems I've used over the past couple decades I would say that Yamaha has been among the most complex and intricate. After nearly a decade of playing the 3000 I was still discovering things that I did not know existed - and I have a pretty analytical mind. That said, the S-950's operating system is quite similar, but guess what - I've spent two months getting this keyboard to sound the way I want, and I'm still not 100-percent happy. That's because many of the things we take for granted within the operating system have either been updated, and in some instances, removed. So, it's back to ground zero again.
Deane is pretty savvy when it comes to working with arranger keyboards, he has owned a lot of them, various brands, and like most of us, he knows what he wants to hear coming out of those speakers. He's quite aware of how to utilize most of the major features on every keyboard he has owned since I've known him, and like many of us, he spends countless hours digging into the bowels of the operating systems these amazing machines. He took a chance with his most recent acquisition, and unfortunately, it didn't do what HE wanted it to do. It's that simple.
Good luck Deane,
Gary