It's 3 months away from being an outdated POS anyway.
Go with nothing pucky, use as is
I've owned the last 3 iPhones. I used screen (and body protectors on all of them)
I've sold every phone (after using them for a year) for $100 MORE than I paid for them brand new.
There is still a market for iPhones (especially the AT&T GMB or whatever ones).
If you want to be able to sell your phone when new ones come out I would suggest protecting it.
Get the non-gloss screen protector.