Well, I only just got my P a short time ago and, apart from some rangefinder issues I've addressed in another thread, I really like it. It handles very nicely, has a good weight, and operates smoothly and easily without being too "fiddly."
That being said, I'm really drawn to the Canon II, III, and IV cameras. I used to have a Leica IIIa, and while it was a bit "fiddly" to use (especially loading), I still enjoyed shooting it. If I got one (and the more I think about it, the more sure I am that I will), I would look for something like a IIIA, or some other model that doesn't have the flash bracket on the side. One thing I love about those Canon models is their appearance, and I feel that the mount on the side spoils the look somewhat. Besides, I wouldn't be interested in using one of those for flash photography anyway.