Feels cheap, doesn't align well, not much better in the distance department
I bought the AK-47 Apex barrel and played with it one time. It's not a bad barrel, but it is not much better than any other upgrade barrel. Compared with my Progressive barrel, the Apex was not nearly as accurate and did not fire considerably farther on a regular basis. With the longshot engaged, the ball dips mid-flight and you have to compensate for this or you'll fire straight into the ground.
The AK shroud was made of what felt like cheap plastic. The entire piece rarely stayed aligned properly and I had to adjust it on a regular basis.
After playing, I sat in my backyard with a tube of marbalizer and alternated my old barrel with the Apex to compare. Quite frankly, I just don't think the inconsistently added distance is worth dropping $50-$100 on it.
I strongly suggest trying one out before you buy it. Personally, I think you can find more consistent barrels for the same price or less.