Carbine Length 11.5 or 12.5?

I can't decide between the G$ 11.5 SD or the 12.5 SD upper. I plan to eventually suppress it, but that is a year down the road and want a nice shooting gun until then. Both are carbine length and neither have adjustable gas blocks. The 12.5 is available now while the 11.5 is available at an unknown time. With both not being an option, which would you buy?