It is legit. Over at PSRTutorial quite a few purchased it and are exremely satisfied with it.

Unfortunately some members over there (with each owning a Genos) did not like this new development (not coming from the Yamaha stable that is) and treated these so bad that this topic went completely sour.

There was a video playing the Genos styles direct on a PSR S970, but I guess they were forced to remove it. (I had this video and it was truly AMAZING to hear the Genos being demonstrated accurately on a mere S970). See that even now they talk about the "Ghenos" instead to try to avoid the flak they received. As far as I understand, this package even includes the Genos Revo Drums.

If I had a S970 upwards, I would already have it on my arranger.