I have to give this board a "middle-of-the-road" rating because I only have limited experience with it. My favorite board in my set up is an Ensoniq ESQ-1. True, the X2 has on-board effects and a "newer" type of synthesis technolgy than the ESQ-1--but in comparison, the X2's sounds seem thin to me. I also like the ESQ-1's keyboard better. The X2's keyboard seems too soft. It doesn't SPRING back as solidly as my ESQ-1 (no the ESQ-1 does not have weighted keys--and neither does the X2). The ESQ-1 seems to communicate with me while I play (keys spring up solidly) whereas the X2 seems to just "do what I tell it to"...(ho, hum). The aftertouch can be pretty cool especially with the "Lead Guitar" patch. I've used the X2 off-and-on for around 3 years now but, honestly, haven't really dove into the thing to test it. It was bought used and I think there may be a problem with the sequencer because I have tried numerous times to record a seqence and I cannot hear the sequence which is already in the machine and I cannot record a new one. Switching sounds on the fly during a gig can be a disappointment. Once you change from Combi to Prog or change a bank, the voice in the board IMMEDICATELY changes. So if you are holding down a chord, the sound will change a little (a combination of the original voice and the "next" voice) when you select the next voice you are going to use. I'm sure that after spending a few more hours with this thing and getting it to make a good, solid sound (and after getting the sequencer up and running), I will enjoy it more. For the time being, I mostly use it in live gigs as a second board because I play 2 boards at once so that I can fatten the band's sound.
KORG skimped on the X2. The sound synthesis seems pretty thin and they tried to "cover" for it by putting on-board effects. Supposedly, you can "fatten" your sound with a bunch or Reverb or whatever. As far as I'm concerned, a cheezy, thin organ with reverb just sounds like a cheezy, thin organ that lingers after you pull your hand back (in horror) from the keyboard. By the way, the organ sounds in the X2 are total CRAP! Get a B3 emulator or a good synth with 3 or more oscillators if you want to create a good, believable organ sound. Even 10 years later, these boards seem to go for $700 to $800! WAY TOO MUCH! I really like KORG equipment but it seems that KORG didn't really offer anything new and exciting with the X2. It's just a production model, middle-of-the-road board...something KORG sold on the market to make a few bucks. KORG has done better with no only their newer boards but with other boards from the same time period.
Keep in mind, I don't use the X2 with a lot of outboard gear. It may sound great for Industrial or House mixes! With some distortion, processing, looping, etc. it may sound good. Personally, I expect a WORKSTATION to stand on it's own without a bunch of other gear. Still, I think the sounds are thin and if someone is going to make Industrial or House and is going to use a bunch of gear anyway...just get a really fat sounding ANALOG synth (like a Clavia Nord, an Access Virus,an old Roland Juno 106, or even an old ESQ-1...which is a digital/anaolog hybrid). In the end, DON'T BUY THIS BOARD.