PP-9000 is the flagship set and quite an event. I had one of these, bought from a department store in Oxford for Christmas in 1981. It's main attraction was the loop, which not only looked cool but was in fact a chicane loop that meant cars going in to the loop side by side crashed into oblivion with infinite coolness...
However, this cost my Mum a sizeable amount of money back then, and I justified its inclusion on my present list because it would use the tons of Powertrack I had leftover. No matter, I was suitably surprised Christmas morning and me and my step brothers spent all Christmas on this set - and boy was it good.
The Porsche and TR7 were both super quick, but the inclusion of the banked curve enabled you to run half the track flat out without risk of coming off - this made for all 'racing' to be done in the twistier sections. The result, whether by accident or design was that this was never boring.
The loop was all metal and fixed to a plastic base with 8 small countersunk screws. The banked curve was new, being made from a stiffer plastic than before and becoming self supporting, without the need for additional supports.
The layout was very big, enabling lots of different layouts that managed to use most if not all section of track. It is worth noting that this set was based on the US Powertrack's stillborn 'World Class Racing' yet features more track.
PP-9000 comprised of:
1 x Porsche 911 Turbo - (all new)
1 x Triumph TR7
8 x 90 degree 9" curve
1 x 9" Track Terminal
4 x 9" Straight
1 x 6" Straight
4 x 15" Straight
1 x 15" Loop (with base)
4 x 45 degree 9" Curve
1 x 12V Mains transformer
2 x Hand controllers
8 x Crash barriers
5 x Bridge supports
