This review is for the microKORG XL+, which is not the original microKORG released around 2001 or the updated XL released in 2008.  The microKORG XL+ came out in 2012, and is basically a further expansion on the virtual analog ("VA") modeling engine used in the XL, plus some additional PCM samples (for example, there is a traditional piano sound and an M1 organ now available).