The XV-5050 has sounds from the original Fantom, the 76 key without the sampler. The sounds on the 5050 you need to compare to a roland XP-60/80. The newer Fantoms (S, X, and XA) all use newer refined sound (the X and the S are more refined yet!) Definately get the newer model such as the the XR if money permits, you cant go wrong.
Phil