have you seen his home/away splits from his texas years?
he was a 4th OF before he went to texas. his "rise" is a product of playing half his games in a little league field.
That, and having a guy linked to Bonds (Andrulis?) as his personal trainer.
Looks like his SLG was helped 100 or slightly more by playing in TX the last 3 years each year, but his avg stayed constant and his OBP the past two years was within .020 points.
[quick edit - actually, his OBP home / away shows .036 gap in '08, so maybe the difference is more significant]