Other than starting up with a ROM style loaded, I can’t think of one thing that differentiates the E50 from the BK9 functionally with respect to turning it on.

But the list of what the BK9 can do that the E50 can’t is long, long, long!

Took me a while to transition from the G/E OS, but once I embraced the strengths, there’s next to nothing I miss. Having 999 Performances available without having to reload a UPS is major if you have more than 128 songs. Not that I have 1000 songs, but what it allows is multiple UPG’s for one song, allowing you far more creative control over each section of a song. This allows you to hit one button (or an FC7 switch) and TOTALLY reconfigure the keyboard Parts for solos, choruses etc..

Once I embraced the system, my time hitting buttons versus playing went to almost zero, and as a busy two handed player, that’s major!

But throw in the chord sequencer, the audio backing and recording, the Key Audio stuff (think of it as audio multipads) the amazing SN guitars and the VK organ, it’s no contest. Yes, there’s a few things that I REALLY wish the dev team had thought about… I wish a Performance loaded up a stored Chord Sequence and a .jpg for a proper chart display in an attached display. But in the big scheme of things, starting up with a ROM style only is pretty insignificant, imho.

The BK9 was something of a last gasp for Roland, and some of the planned for features never materialized (there are hooks inside for expansion sounds that never got developed) and some of the best features like the Key audio had zero factory content, which would have pushed it ahead of its competitors had it been provided.

But as is, out of the box, it is IMHO the greatest arranger/backing keyboard Roland ever made, and featherweight to boot! Don’t worry too much about minor stuff the E50 could do. Enjoy the amazing stuff the BK9 CAN do! 🎹♥️