If your intention is to sell the card, then you might want to stick with PSA to receive the highest resale value. But you roll the dice on having the grade drop half a point. You know this game, it depends on how the grader feels that day. If you're going to keep it, then why bother with the reholder. If you are a collector that has to have it in a holder and it's not for resale, then send it to SGC, however the grading fee may be higher than the PSA reholder fee and you run the same risk of the grader having a good or bad day.
If it were mine, I'd keep it as is.