The Roland RS50 is more than the QS6 because of it's sounds. The Alesis is now an older keyboard. The samples, although good, are from samples Alesis did several years ago. Alesis, although bought out last year by Gemini, a DJ equipment company, has re-introduced the QS line at lower prices but have not redesigned these keyboards. When Roland came out with the RS50 this year, they put in new samples from products like the Fantom, etc. So, comparing the pianos on the Roland vs the Alesis, I like the roland better. There is also a Yamaha S03 which sells for around $499.00. It too is a nice sounding keyboard, featuring many sounds from the S80 keyboard and also including XG sounds. As for the keyboards, the Roland and Alesis feel better than the Yamaha. Without looking at arranger keyboards such as the Yamaha DGX300 or the Yamaha PSR550, the Roland and Yamaha would be my best advice to you.
George Kaye
Kaye's Music Scene
Reseda, California