I own a 2003 Les Paul studio...I dont know if things have changed since then, but my studio has a maple top. When I got mine, both the Studio and The standard used the same pickups,(think they were 490T and 418s or summin like that...but with Alnico magnets.) at that time, as far as I know, the only mahor difference was that the studio had no binding and the standard did.
The wood is probably also of a slightly higher quality if you shell out for a standard...but all in all, both models, great as they are, are overpriced.