Armalite AR-10 Magazine Deal

http://www.cdnninvestments.com/ar320lefamag.html

I've called and confirmed that these are used factory Armalite 20rd magazines with the plunger-style follower.

Sorry I'm stupid. But does the "plunger style follower" mean it's the crappy modified m-14 mags or the new and improved mags they made recently?

It means that it's the second-gen follower, not the (new) third gen follower. As to whether that's crappy, that's your call. My second gen followers have been flawless for thousands of rounds.