I actually like the mag release on the PSP. I admit that my initial impression of the release system was not good, but that was an inexperienced and uneducated one. If you are using the gun where speed of mag change is an issue, then yes, the M8 will be a bit faster, as you can release and grab another mag at the same time. The PSP requires you to use two hands to release the mag. Being that I don't compete with a P7, my life is not dependent on it, and I don't let my mags hit the ground with any P7's, it's not any faster at all because I still grab the mag anyway. I would argue that the heel system is more reliable and less likely to fail. I don't push it like a button. I just grab the whole butt of the gun with my thumb on the button, and my fingers on the front of the mag extension, I pull it out in one continuous motion. No mag release button to try and find or hit by accident. Quite a nice system if you ask me. If I am taking a P7 to the range, it's the PSP that is going.
Auction is at $1900+15%=$2185 Happy biding.