I personally don't think they are.
Pros:
-They do have a "no tilt" follower. You can't make the follower tilt and jam like you can on aluminum mags because the follower runs on "rails" in the mag body. I think it is a gimmick myself.
An interesting fact about that. The Magpul .308 mags don't have this feature....
-You can run over them with a truck and still shoot them if that is important in your daily life.
-The little dust over can be snapped onto the base and is actually very useful for unloading magazines. (The only reason I kept 1 out of the 100 that I bought
)
-They supposedly have a continuous feed curve instead of having a straight to curved transition point that aluminum mags do. I don't know this for sure, I have never cut one in half to measure it.
-They don't make a noticable rattle if you jump up and down in a chest harness like aluminum mags do.
-They look cool and can be color coordinated with your Mag-pul furniture. (There are some people that really worry about this)
Cons from my exerience:
-Some problems with colors other than black. I didn't have issues (I had OD) but I know some guys that had some crack in FDE.
-Designed to fit the M-16 magwell not a STANAG magwell. Won't fit in other guns that have a STANAG well that will run Aluminum. Like HK 416, FN SCAR, FS 2000, etc.
-Can cause damage in FN SCAR by causing the bolt stop to ride on the bottom of the carrier unless you modify them. (My brother runs a SCAR alot and we share mags when shooting)
-Won't fit in a pouch made for 2 aluminum mags easily. Too tight and when you try to pull one mag out, sometimes 2 come out instead.
-I am alway suspicious of the "next new thing" and alot of the PMAG info sounded suspiciously like the stuff that was said about the HK "High reliability" mags when they 1st came out. They didn't really live up to the hype either.
-I just didn't like them for some reason and I have never had an issue with aluminum mags, even old pre-ban black follower mags.
Of course, YMMV.
Didn't you get PMags when you bought your LWRC's? I thought they shipped with them standard.