Upgraded functionality overnight - Aero Precision AR15 Ambidextrous Bolt Release ,PDQ

Don't want to spend $400 on a factory ambidextrous lower? Then this is you ticket to the ambi life for you!

I cannot say enough how much of an ergonomic improvement this part is. The underrated superpower is the ability to lock open the bolt without having to use the pong-paddle exclusively. It is so. Much. Better! In double feed drills especially, being able to index finger up and lock the bolt back makes it go so much faster without having to remove your hand from fire control.
Speaking of faster, on 1-1 drills, or any drill where the reload is timed, I'm able to consistently get .1 to .12 Seconds off my reload times. It's that good.
The only real issue is the installation. If you've got the 4mm milling bit and tools to do it at home, power to you. I had to go to my local gunsmith to have the receiver cut made, but it only took them half an hour of labor and it looks and works great. Be aware that depending on choice of dust cover, the pressure exerted on the PDQ lever might be enough to close your bolt. It's rare, but I've determined that to be the cause of the mysterious bolt drop after I installed this device.

Overall, I think it's a great way to get much improved functionality out of any traditional AR lower and really improve the ergonomics of an already wonderfully designed rifle!