from the photo, it looks like the P1 has the panning base on top -- if so, it would be a nice, compact solution for panoramas (i just ordered the relatively heavy and expensive RRS panning head after researching alternatives)
speaking of RRS heads, i have the 40 and the 25. the 40 has a very unpleasant stick-slip characteristic which i've mostly overcome by applying dry lubricant to the ball (Joe agrees this is a characteristic of friction materials used and that applying a lubricant is the solution - but then you have to worry about keeping the ball clean - the dry lubricant doesn't seem to pick up dirt, but has to be re-applied periodically). that said, there is always camera movement on lockup. the 25 (which i use on a very light travel tripod) doesn't have this problem, but then it doesn't have an adjustable drag or indendent pan, limiting it's usefulness.
i also have a linhof on heavier tripod - it has significantly better feel than the BH-45, but is a bit heavy and bulky for packing and travel
definitely room for improvement in light to medium weight heads