Yeah, I took a closer look at the online manual for that EK-50. At first glance, it doesn't really look like it has much when you look at the control panel. But there is a lot of good stuff there: the ability to layer 3 voices on the right side of the keyboard, roughly 150 different effects (and it appears to have the ability to layer two effects at once, independently on the right and left sides of a split keyboard), as well as hundreds of sounds and styles.
But there are some questions that either were not answered in the manual, or I just did not look deep enough to find those answers. For example, you can layer 3 sounds on the right hand side, but can you adjust the volume of each sound independently? And I saw where you can change the octave of the sound, but again, can the octave be set for each of the 3 layered sounds independently? If not, then this is a serious shortcoming. The keyboard does have some kind of recording function, but is it multi-tracking, like on the Yamaha E400 series keyboards (at least the E433 on up)? On the Yamaha, we can record 5 independent tracks -- each containing 2 layered sounds (main and dual voice), along with a 6th accompaniment/rhythm track. I am not sure about the recording capabilities of the EK-50, but my hunch, based on the online manual and specs I saw on Sweetwater.com, is that it can record 4 "melody" parts, and can include 8 accompaniment parts, which would likely be based on the style selected and not freely editable -- kind of like what our Yamahas record on the accompaniment track. It is also not clear to me if the 4 melody tracks can each have up to 3 layered sounds, or if these tracks can be only one sound each. I know on many of the Casios, they say they have a "17 track" sequencer, but only one of the tracks can include layered sounds, while all the rest can only be a single sound/voice.
There does seem to be some ability to modify the styles, and it may even be to possible load additional voices.
And there does appear to be 40 of what we call registrations (they call them "keyboard sets"), set up as 10 banks of 4, but it is not clear whether the rhythm/style can be "frozen" so that you can change the keyboard set during a song, to get a different sound, without changing the background rhythm or style at the same time. And I saw no mention of any kind of synth functions, like filter, envelope generator, or portamento.
Please keep in mind that I have zero firsthand experience with this keyboard, and I got all of this info online, so if anyone who has had or does have this keyboard wants to correct me, certainly please do so. This means, of course, that I also have no idea as to how good the key feel of the keyboard is.
I currently see this keyboard on Sweetwater.com for about $550 US, and there is a Korg EK-50L, which has more onboard amp/speaker power and additional sounds, for $100 more. That's getting up there, and into the territory of something like, say, a gently used PSR-S670. There seems to be a lot there, but at this point, not enough that would make me want to jump off the Yamaha ship.
Finally, again, I realize this is PSRTutorial, and not KORGTutorial, so I apologize if I'm stepping over the line. But I do feel it is good to discuss what the competition offers, especially as we are all waiting for our updated models, so we can all make informed buying decisions, and perhaps also to discuss what features are important so that Yamaha can consider implementing them into their own future keyboards.