Performance enhanced Triton series. Mostly the same sample set with more performance buttons and knobs for doing macros and so on. A little complex to use but very flexible/expandable.
No particular issues I know of. My friend had a lot of trouble figuring out how to sequence with the thing. Korg has been helpful on a lot of aspects. Be sure to get the right expansion cards. Names can be confusing. I had to repair the board that took a hit and cracked under the sequencer buttons. I now have a Karma! Whowhoo! (And thanks to the guys at Hansen Music in Billings, MT who donated the MOSS board and a couple expasions!!)
Also my AT sensor has been troublesome. Has a crack developing apparently. It would work propped but now it's dead again i see.