There is a post below from a long-time Yamaha user who sent his back after a few days. I'm a PSR 900 user for over three years, and it took me quite a while to wire that board. So I think one should probably take 3 to 4 weeks before coming to a conclusion. So understand, this write-up, hugely favorable, is after only three days. So please take it with a grain of salt!
"I just got my 600 Friday afternoon. I was grateful for Stuart at Sweetwater taking my order a couple of months ago and shipping me one as soon as they got one.
I have a Kronos, a Yamaha PSR 900, and a Roland XP50. I have a Hammond B with Leslie and a Suitcase 88 Fender Rhodes in the garage. That just to put in perspective my thoughts on the 600.
For the dollars, it is amazing. Now granted, I'm still going in circles with the operating system because this old dog takes a while to figure out new technology. It's no Tyros, but with $3,000 left in my pocket for choosing the 600, I'd say I came out way ahead.
I love my Yamaha 900, but like all keyboards, there are so many things to not like. Drums suck. Arrangements are too nice (artificial, plastic). Registration system is a nightmare.
What to love about the 600? 1) Bang for the buck. 2) Good keyboard sounds. 3)Really nice horn sounds--especially the trumpets and cornets. (Have to agree, a bit put off by the strings.) 4). Touch screen. I'm an iPod, iPad, iPhone type of guy. I keep trying to touchscreen my Yamaha (pathetic isn't it?). 5). Great speakers. 6) The balance knob! What a simple idea that Yamaha didn't think of. 7) Really riveting styles-- edgy, more contemporary, with raging guitars and intense drums. Even the ballads and waltzes have attitude.
. Decent keybed, but I am spoiled by the Kronos 61-- again like comparing a VW Bug to a Porsche. 9) The songbook that lets me simply save songs, styles, and mp3's just the way I want them and then do them without a huge hassle. 10). The improved GM soundset. In the old days, Korg implementation seemed really weak side by side with Yamaha or Roland. Now I actually liked some of my midis better on the 600 than the Yamaha. (I mainly buy midi files from Yamaha to print out keyboard, string, brass, and bass parts for the band-- they read better than they fake it....)I've got sounds, like everybody, that I wish had been implemented better or more accurately sampled. There are quirks in the operating system that for me might be worked out. But after three days, I'm liking what I'm getting from this beast. I'm preparing for a show in two weeks and I've recorded some of my Sonar creations to mp3's and have stripped a few of my sequences of tracks for storage in the 600. The Kronos is an awesome live performance animal and I'm hoping the 600 is too.
So can ya tell? I like this critter. Korg's packed a lot of goodies into this little board and for not a lot of bucks. And maybe, when I learn how to edit. sounds, I'll be even more jazzed (Ain't hope a friend in need?)"