I sold the pictured BCM yesterday. I too prefer a midlength (9") gas system to a carbine (7") for obvious reasons. I've been trying to sell off my DI guns since I currently have a mildly concerning love affair with LWRC's piston system. I'll keep one Colt 6520 and 6920 (the 6520 is a great lightweight KISS CAR and the 6920 is iconic).

If I were selecting a DI rifle for WROL / TEOTWAWKI it would be a hammer forged BCM Midlength. Period. I've owned 3 BCM Mids (2 HF and 1 Non HF). They've all performed flawlessly. I cannot say that about the countless other DI ARs I've owned (including Colt).

IMHO, it is impossible to beat (overall) a Glock. I say "overall" because they are guns with better ergos; more accurate; more attractive finish/design; etc. However, there isn't a more durable, simple to use, easy to maintain, reliable and reasonably accurate handgun.

Selecting guns that you MAY have to rely on until the end of your days is a challenge.