I would do it. Not only are you getting a gen 4 but you're getting a 40. I have a 26 and I would love to trade for a 27. It all depends on you though. If you prefer the 27 then do it. Don't let the fact that it's new be your sole reason for choosing to do it.
Guns don't kill people, bullets do.
Amani Na Upendo
Peace and Love,