No as I heard they still leak (the STANAG one). But you can fix them, you can find how on the forum.

Gen2 Mags are supposed to be much better than first gen; I have a few Gen1 mags that leaks, bought conversion kit to Gen2 (20$ each) to fix that up, we'll see how this goes. It doesn't mean that they won't ever leak though, as most mag will eventually leak at some point.

KWA's pistol mags are pretty solid in that regard; Never had any that leak, and I have yet to hear about people having issues with them. Their LM4 Mags tend to have leaks though, but not as bad as WE's as they are often located in the valve. Just tightening the valve and/or lubing the valve's o-ring usually fix the issues.

I *think* WE's Gen2 Mags are similar in design to KWA's when it comes to the gas chamber and gaskets, so....

Almost every gas mag I've had, pistol, rifle, and PDW has leaked. TM, Marushing, KWA, KSC, Tanaka, it doesn't matter. The ones that haven't leaked are probably going to leak this spring.

In most cases the leak is easy to fix and stay fixed. The Gen 1 WE mags are a bit finicky so if you're buying new it's definitely worth the extra legwork to get Gen 2s.

WE's Gen 2 Stanags are great, as far as leaking goes. I've had mine since they came out earlier in the year and none of them have had any problems. I even stopped using silicone oil for the seals for the most part. I haven't gamed at all this winter and my mags are in storage. They've all held their gas since November to this day.

I haven't seen anything about KJW. Are they unreliable?

Kjw m4 by tanio koba is the most reliable gbbr out of the box but it's unpopular because of the weak recoil and rubber band bcg. Get the we open bolt system. It's more beginner friendly. My humble opinion: all gbbrs are a money pit and if you're not willing to spend, you're better off saving your money.

KJ's great, the popularity only dropped because the WE open bolt system is just as good but doesn't use thermold mags

Get the WE you won't regret it. They are excellent platforms that WE has recently made great improvements. And if it does break on you parts are exceptionally easy to find. Heck my WE is fully RA-tech upgraded and it isn't a money pit.

Get the Ra tech version of we. Gen 2 mags and u r all set. Worth money if u r looking for realism. And the ra tech not that bad in price

I love my WE PDW. shoots great and consistent, recoil feels great and is really reliable.

For the price, I was really impressed with my WE G39C, gotta start somewhere right?