I personally prefer tying a piece of cord around gas-key, dangling the cord out of the back of the receiver, and attaching some type of handle so I can charge my AR like I'm starting a chainsaw or a lawnmower or something.
1. Rainier Raptor
2. BCM w/ Med latch
3. Normal 'mil-spec' shit
The raptor is truly ambidextrous which is nice. If you have ever held one, they feel extremely solid. The right latch is larger than the left to properly compensate for the forward assist being there. The ONLY issue I have is that I run a magnifier and it makes it a little cramped on the right side whenever the magnifier is flipped down but I typically charge from the left anyways so it is a very minor issue and if i needed to charge from the right, I can just come from underneath. I honestly think the design is very well thought out. I do not own one but I have played around with one for a few hours and gave it a pretty close inspection.... i will own one eventually. A+ shit
The BCM is half the price of the raptor so you are going to get a lot of claims that it is superior bc the higher volume of people that run one... it is a very well designed CH but is definitely out performed by the Rainier Arms. People don't want to pay the price required to get the best but then they want to claim that the discounted item that they bought is somehow far superior to the item that they didn't want to pay for.... I call it PSA syndrome.
Just because something is more expensive obviously doesn't mean it is better, but price aside, the Rainier CH feels and functions better.
If you are running a suppressed DI rifle, the PRI charging handle is a pretty good choice.