It's kind of what I expected. The vocal harmonizer sounds okay but external units do a lot job better in many cases. There might be a few tricks that could make the vocal harmonies sound a lot better and I see where Dave has experimented with various settings to get a desired result. Korg apparently put in a lesser quality unit than what's in the Pa3X, although that's just my opinion based on what I've heard from various online demos, including Dave's. Others have stated the same thing so it seems the observation is a correct one. You have to pay thousands of dollars more for a Pa3X which makes the trade off a lot less appealing. In other words, the Pa-900 is a lot better deal for the money and thus most people probably won't mind the less than stellar harmonizer on the Pa-900.

Dave's voice is really good to begin with and so it's somewhat of a disappointment that the harmonizer isn't up to snuff, which would have made the song(s) even more enjoyable if in fact it was up to snuff. Oh well.

Another possibility would be for Korg to provide a software update to improve the vocal harmonizer. Whether they choose to do it is another story. To my ears it sounds about as good as the PSR-s950 harmonizer. Korg could really improve overall sales on their mid-range arrangers if they decided to put in stellar harmonizers. Same goes for Yamaha. I'm guessing roughly 50% of keyboard players like to sing along when playing. Charge a $100 more and put in an excellent harmonizer. Makes sense to me.

Perhaps TC-Helicon conspired with Korg to make owners somewhat dissatisfied in an effort to get people to shell out big bucks for an external unit from TC-Helicon! A little farfetched perhaps but stranger things have happened. In conclusion, it appears the Pa-900 harmonizer lacks somewhat and therefore an external unit is advisable, especially if you perform live in front of a crowd.

All the best, Mike