I've owned the P6, P8 and P10. The P6 is a very good turntable. The P8 is similar but noticeably better. The P10 sounds quite different, and is not necessarily an improvement, depending on personal preference. Personally, I prefer the P8 to the P10, which I find bright and somewhat brittle sounding.
As you like the P6, and the P8 is an improved version of the same sound, it is an easy recommendation. You can always improve the P8 later by replacing the arm with the RB3000, which is another modest but noticeable improvement.