
I’ve had 30 years of experience fighting with keyboard instruments in both church services and for musicals.
Electronic keyboards are very much a case of getting what you pay for, up to a certain point. However, beyond a certain price point (~$2k), each brand has a few unique characteristics and then a few features that are made more or less usable as you upgrade for other features.
In playing a couple weekends with the Roland HP-603A, I discovered a few of these.
Dual sound:

The dual sound on this digital piano has an option that I haven’t found on other keyboards (Kurzweil, Yamaha)… you can specify the balance of the sound between the two voices.
However, just like the Kurzweil and Yamaha, the order of selection when selecting two voices determines the “primary” voice. You can separately select to “edit” voice 1 and voice 2 and scroll through options, but that’s not as useful while playing.
Organ sounds:
The Roland has a few organ settings, 2 or 3 which are “pipe organ” and a few which are “jazz/gospel/electronic organ”, but one interesting one that I found was the “Nason Flute 8′”… which is an oddly specific description, but is a good instrument for quiet underscoring but with a breathy “flute” attack.
The organ notes sustain in response to the damper pedal on the keyboard, which is totally wrong, but very convenient. (The Kurzweil does the same, but the Yamaha that I have does not.) Trills on the organ settings articulate distinctly, but are not as detached as I’ve experienced on a Yamaha.
As far as I could tell, the organ settings *do* respond to attack, which is a little bit weird and/or surprising, but you just have to make sure not to suddenly emphasize random notes.
Transpose:
Transposition has a transpose button and then you + or – the transposition. About half the keyboards I’ve used have made it either non-obvious *how* to transpose, or made it slightly difficult to pull it off relatively quickly.
Strings and Bass:
The “Symphonic Strings” setting had a nice sound without being too slow on the attack or too harsh. I almost always use strings as an ambient addition to a piano-like instrument selection, so I didn’t try actually leading with the instrument.
This is the first keyboard that I’ve seen in a while, however, that *didn’t* have a string bass + ride option. The walking bass on the left hand just becomes more obvious when a ride cymbal is tapping along.
Conclusion:
While I’m not sure that I’d purchase one for my own home, the Roland works better in an accompaniment situation than the mid 4-figure Yamahas in my experience.