I'll stick with my ar in 9mm.. If you want to get something in the Kel Tec price point to reiterate what others have said you can build a 9mm ar fairly cheap..
I still carry my old 228's daily.. Keep thinking about moving to the 229's but other than being the newer version with a couple more rounds in the mag I can't find a reason to change.
I've been looking at the creedmoor. Seems the general consensus is that the Grendel is built for short action weapons such as the ar platform and the creedmoore is the long action round which equates to more powder creating greater FPS and more suitable for long range weapons.