The P4 is a good micro tool. My favorite. It's still a micro tool though. There isn't as much metal to back up the pliers for really hard use as compared to the standard line of Leatherman. Nothing locks. Because the handle is small, the pliers are spring loaded to open back up. That's a nice touch.
I like it in combination with the Micra as a good lightweight set. Small and convenient when the bulk and weight of more is overkill. I think they make an excellent backpack set.
The P4 awl is the best shaped Leatherman awl IMHO and sharper too than the Juice awls. If you mostly want a small pliers, small file, small awl, then it's a good addition to your kit. If you want more, you'll have to combine it with another tool, or buy a bigger multitool.
Phil