I went ahead and compiled his minor league splits. They'll also be useful for future discussions.
Against LHP (450 PA's)
.281/.361/.413, 12% BB, 19% K & .132 ISO
Against RHP (1202 PA's)
.287/.377/.416, 12% BB, 18% K & .129 ISO
note - these numbers don't include HBP or SF because the minor league stats pages don't list them individually.
Those are pretty identical numbers, Pompey looks to be the rare switch hitter who doesn't have a "natural" side.