"Sure the PI curve is generally higher and a little more erratic"
This is normal. There is no official support from CD Speed for Pioneer drives, the PI results are not accurate because it doesn't count with the right ECC, so actually CD Speed reports about 8 times the amount of PI you would theorically get.
I already tried to manually modify the ECC setting by tweaking the registry settings but it didn't work.
About PIF, there is a strange thing. Pioneer drives don't report PIF but PO which in theory are not the same. So I wonder what does CD Speed take into account to report PIF.
What I noticed, though, is that the PIF report in CD Speed with my 109 is rather consistent with the PIF report on my Benq 1620 with the same discs, so even if HOW it's possible is a mistery to me, the good news is that you may trust PIF report when scanning with Cd Speed on a Pioneer drive (at least on the 109). I'm glad to learn that a 108 owner can confirm this.
Would you post some of your scans, I'm curious