Well, I\'ve got to using my P3s a little now, black, white and the entire green and purple/pink range, and I\'ve been very impressed thus far. Coverage on some of the colours is simply astounding (Carnal pink for example, a light shade, especially so). This means they can be thinned a hell of a lot more than citadel paints leading to smoother coverage, I also believe the paints themselves to be slightly smoother naturally. I\'ve found myself adding two or even three times as much medium to get things as thin as I would like (my technique invloves very thin paints using the transparency to blend). This can be a negative as well though, it does make smooth transitions harder if the colour you\'re layering is a few steps away from the one below. (as an example I had to add in an extra couple of steps when layering pink with less stark differences between layers)
Biggest negative would have to be the satin finish they produce, easily solved by a quick spray of dullcoat but some don\'t have matt varnish and when working with them it can occasionally be difficult to just just how smooth transitions are, inperfections that become apparent when matt spray is used. Also due to the need to thin so much I have noticed a little separation, easily solved with a swish of the brush though. Slight gripe in that some colours/highlights are very close together, whilst the next step is a large jump. (For example Murdrous Magenta and Sanguine highlight are very similar, leaving a very large gap to carnal pink) makes the range seem a little more limited, but just takes a bit more mixing.
All in all I believe their nature requires a slightly different approach and technique so they may take some getting used to by those like myself heavily set in their ways, but I\'m of the opinion that they do perhaps have the edge of GW and Vallejo. Certainly even with these issues and my unfamiliarity with the range my first attempt produced comparable results in blending transition and improved smoothness of coverage.
And to answer bobert, I\'d say yes, I much prefer the p3 white to any other I\'ve tried so far.