The LG Chocolate, also known as the #LGVX8550, is LG's enhancement to the original LG VX8500. Compared to the original, the Chocolate features an improved touch controls with vibrational feedback, a navigational whee, a change in the key layouy, an updated music player and a smoother design.
The usual 1.3 megapixel camera is still included in the package. However, the new Chocolate added a lock switch on the side of the phone in order to prevent accidental calls while the phone is in the user's pocket.
The LG VX8550 is indeed an improvement to the original VX8500, both design-wise and in quality.