The PPS LT valve is quieter but more importantly will be more efficient and actually allow you to run a lighter mainspring.
The AKALMP valve allows you to run lower input pressures, but that does not mean it uses lighter springs. The PPS would be my preferred valve even if it cost the same as an AKALMP valve. Both are upgrades to the CCM valve performance wise. Not to say that CCM valves are anything but nice valves.
"I'll see it when I believe it"
PSA: Please don't use photobucket to post images. When you go through one of the older picture threads and find a lot of dead photo links, it is because of photobucket. They limit the amount of bandwidth your free subscription pictures can use, and then make the photo unviewable. Please use imgur.com or another free image host that does not ruin picture threads.