At this price point, the features are very similar and it becomes an item for item check list of likes/don't likes. The S900 definitely has the advantage in features; it even has the harmonizer, but the price is higher too. The Roland E-60 has the advantage of 76 keys, which for me is a very big, determining factor. My opinion is, that if you play piano style for a significant portion of your time the 76 notes make a difference. The Korg is making great impressions with this PA series and if you ike Korg sounds and styles, the PA500 is comparable to the S700 or E50.

All I can say, you have the mid-range keyboards of the top three manufacturers to choose from. What you gain with one, you will lose on the other. You'll have to listen and play. It may come down to something as simple as panel layout or a feature that only you think is important. They are all good choices. My pick is the E60, but...