||I bought these mags (not from GI, sorry!) locally...they're pretty good, but not perfect. Since these are just mags, I'm going to do a simple pro/con list.
Sturdy feel, feel like metal
Work perfectly in my ECHO 1 MP5 and other guns (according to other reviews)
Of the 8 mags, one of them came broken
Kind of hard to insert into your gun...not a confident *click* when they're in
I'm not sure they really fit 90 rounds...I've got a tube that I use to load the mag (I push the BBs through the tube into the mag) that holds 25 rounds, and I usually only get 3 full tubes and a little bit of the last one
All in all, 8 mags for this price is a good deal. Though my MP5 high cap is perfect, many people say mid-caps are the way to go, and my MP5 is my sneakier weapon so it's important I'm not rattling as I move the gun.
Rating: [4 of 5 Stars!]