I purchased these about a year ago, and I've got to say, they are quite reliable.
They hold 120 rounds which is more than enough and the fact that they are only $65 are great for a box of ten.
They can hold 120rds
There isn't any obnoxious rattling
The Plastic (can also be a con), it doesn't scratch as much as metal mags
Made of plastic, doesn't give a satisfying sound when reloading
Also feels a bit chunky.
Rating: [4 of 5 Stars!]