Agent P as in Perry the Platapus? I saw him at a meet and greet in Innovations during the party on the 15th.

We didn't stop but he was there.
My friend and I started in Toon Town just after six. We walked onto Roger Rabbit, did a few of the treat trails, I rode Goofy's coaster and then we headed out to the other treat trails. We trick or treated most of the night and had an absolute blast! We actually caught the parade twice totally by accident although we didn't stay for the whole parade the second time. I don't know the weight of our loot but I completely filled my backpack and then filled it 3/4 of the way again. My goal had been to fill it once but it was just so much fun going around that my friend got a locker, we dumped what we had already gotten, and then we went around some more. We went through the trail at the Golden Horsheshoe probably 7 or 8 times back to back as it was pretty much a walk through during the fireworks (some of which you could see but certainly not all the cool effects) and they had the Werthers caramel apple candies. My friend had tried one and then we went back to get more since she loved them so much.
Highlights for us, besides the trick or treating, were listening to the Cadaver Dans and seeing the villians say goodnight at the end. I didn't realize they did that little show to close out the night and we caught it purely by chance. It was also awesome to see all the cool costumes. My favorite by far was a couple dressed as Belle and the Beast. They had recently gotten engaged and just seemed so happy and in love. It doesn't hurt that Beauty and the Beast is my favorite Disney movie from childhood.
Crowds didn't seem bad to us at all. We had been there since Saturday and it was by far better than any of the other afternoons or evenings.
There was only one treat trail we didn't like and it was the one that went up to the monorail platform. I am not quite sure why it was so much slower than the others but for us it was. We did it fairly early in the evening and never went back to it. As we came down from it and saw how much further backed up it was I just cringed to think how long those people would be in that one line. The Innovations line which was also nearby moved along just fine. I'm kind of curious if others had a different experience with the monorail treat trail.
For those of you worried about the negative reviews just go with some excitement and open mind and you will have a great time. The friend who went with me thought it was a waste of money and that it would be boring. She has been talking it up to friends and family and is planning on going again next year.