I thought all Squirts were created equal. I got my second Squirt model today, a P4 and I instantly noticed a couple of differences. The first one, well, besides the different plier head (duh!) was the lack of tweezers. As you can see, the P4 (blue one) has a small reamer/awl instead of the removeable tweezers found on the E4 (red one).
The other interesting difference is the simplified phillips driver, similar to the one found on the Micra- basically a hunk of metal that comes more or less to a point, rather than the E4's actual 4 pointed phillips head.
I kind of like the P4, especially since I don't do much electrical work. I once tried to build a model car with a small motor in it. The car burst into flames as soon as I installed the AA batteries. It didn't even wait for me to turn it on. I took that as an omen to stay far away from electricity! I think I prefer the phillips on the E4 though, but I think overall I would get more use out of the standard plier head on the P4, plus I rarely use tweezers. If I need them, I usually also have a SAK, but then that also usually covers the awl as well, so I guess it's redundant either way.
Def