James,
The Lionstracs X-R piano sounds very good even in the middle registers. Usually in many keyboards, the higher end of the piano and the lower end piano sound great but the middle zone seems a little tinny... but in this case its quite good.In addition, I think the Oasys keybed is also allowing you to play with more dynamics. Good combination of the Oasys and Groovetracks module you got there.
And thanks for the very good review on the Pa3X
Cheers and happy playing.