Having had both, can you comment on the differences in sounds and styles between the two kb?
Well, I don't remember a difference in sounds or styles between the 3x and the 900. I've been using the Yamaha 950 for the last while, and I kinda forgot what the 3x sounded like. I will say that, like always, the Yamaha styles behave better for my "middle of the road stuff." I once equated Korg to Steve Gadd, and Yamaha to Ringo Star - both fantastic drummers, but Ringo knew just how much NOT to play. The Korg styles, in general, are a bit busy ... still.
I might just be "over Yamahized", but I find the key action of this 900 to be FANTASTIC. Better than I remember in the 3x. It's solid, responsive and very comfortable to play. That's one reason I'm trying so hard to make the other stuff work for me.
I never heard a harmonizer that I really liked ...
Wow - we differ there, my friend. I have been using harmonizers for 20 years, and gotten so much favorable reaction to the end result that I made it part of "my sound". I understand how many DO overuse it, but frequent use and OVER use are two separate things. I use it a lot, but I sing very differently when I use it - I think like a member of an ensemble, and not a lead singer ... I emulate my favorite vocal groups and try to capute the style of the song with the backgrounds blended in with the leads. Some of my favorite influences are:
Four Aces, Four Freshman, Four Lads, Manhattan Transfer, The Carpenters, Mills Brothers & Andrews Sisters (Yeah, I know - mostly OLD dead folks!)
I'm getting closer to the setup I want, and as soon as I'm there - I will do some dedicated recording of my "how to" use a harmonizer. I believe it's SO much more than hitting the footswitch to turn it on. It's a mindset and a change of approach.
As a solo entertainer, it's become a huge part of my sound to incorporate harmony, even if it's just on the main chorus parts of songs. My specialty numbers benefit from more intricate usage, but even an old, tired song like "Old Time R&R" comes alive when you add the harmonies to the chorus. It's just lifeless and boring with one, lonely voice singing that mid section.
In a more contemporary vein, Jason Mraz's "I'm Yours", Train's "Soul Sister" and Bruno Mars' "Lazy or Just the Way You Are" all shine like the sun with harmony on the chorus. As I mention it, Colbie Calait's "Brighter than the Sun" is another fine example.
So many songs can be spiced up with a tasteful addition of vocal harmony. Remember ... most of our audiences are NOT players, but I'll bet MOST like to sing ... at least in private. People relate to words, so I give 'em their fill!