[Optimus Vader]

If you plan on selling it down the line I wouldn't open it. If you don't plan on selling it, you can always do the old "carefully slice around the bubble" opening technique to preserve the cool packaging and put him back in it to display that way down the line.

And what is the difference in opening the one you have, or buying another one at TRU to keep this MOC? The difference is you're spending an extra $50 on a second one (that you wouldn't get if you already had an opened one) which is probably the profit you'd make by selling your MOC SDCC version. So even financially I see it as a wash.