I'd probably say that this keyboard really needs the FC-7 footswitch unit...
I agree that there is much that is buried in sub-menus, and without a touch screen or the iPad app, they are often a pain to get to, live. Mind you, so does everything else (bury things you need), but touch screens allow you to get to them much faster. However, most of the things you are likely to want to change while actually playing can be placed on the FC-7 or the four Assign Switches. That's eleven commands (that you get to choose which) in addition to what the buttons can already do.
One of the advantages of the dual screen that I have found so far is that you can display lyrics AND still see what is going on with the arranger (mixer, drawbar settings, stuff like that) - most arrangers, the lyrics preclude seeing anything else, but I completely agree that Roland should have stuck with the E/G series touch screens. However, in their defense, I'll point out that the BK-9 came out well after the BK-5/3/7m, and, as budget arrangers, they couldn't afford the touch screen. I really doubt anything but a major redesign of the OS would allow the BK-9 to have a touch screen system as it is based on the OS of those cheaper arrangers. Many manufacturers design the flagship first, then spin off the MOTL and BOTL arrangers from that. But this time, Roland designed the BOTL first.
The Hammond sim MUST have an expression pedal. Just as a real B3 does. Try playing a B3 without touching the swell pedal, and you'll find things getting shrill up top just like the BK-9 does..!
I'd be interested in whether the legacy styles play well on the BK-7m, but not on the BK-9. And whether they are actual Roland styles, or conversions. Most older styles that I've loaded play OK. Naturally, everything needs Makeup Tooling to address the newer sounds and drumkits, and there is some work needed to tweak for the kits (old styles made no difference between a high velocity low volume drum Part and a low velocity, high volume Part, but now there is a huge difference, thank God!). I think it is pretty unreasonable to expect a 20 year old style to play on a 21st century arranger, and sound spot on. But as long as all the intros, endings, variations and fills work, the rest is easy (IMO).
BTW, while we are on the Makeup Tools, I haven't found any difference yet between the G70/E890 Makeup Tools capabilities and the BK-9's. The only difference is how easy the touch screen made it.
As to the default Mastering Tools EQ and compression presets... I think you may have your Bose a bit bass heavy (they always seem over hyped in the bass and treble to my ears anyway!) but on my studio nearfields (Mackie HR824's, so bass is tight and solid) I agree that it is a hair over the top, but nothing I'd call muddy. All I did was dial the main preset back a db or two on the highs and lows, and things seem pretty spot on. Those Bose already have a huge 'smile' on the sound, I think that is where the extra mud is coming from. I don't see how a 3 band semi parametric EQ is any more complicated than any other arranger... they ALL pretty much have a 3 band EQ these days, don't they? Truth is, the Mastering section is identical to your E50/80 and BK-7m. Only the display style changes from the E series. You managed OK with that, didn't you?
Perhaps we can get together on the Roland-arranger.com site, and I'll try to help you with getting up to speed on the BK-9. Admittedly, I play almost exactly the opposite of what you do, I rarely play anything to the 60+ crowd, but I'm starting to get a feel for the thing now. It still keeps surprising me with how good it can be. It is just a completely different beast from the G70, OS-wise.
Thanks for the review...
_________________________
An arranger is just a tool. What matters is what you build with it..!