Why are you using an outdated scaning program? Google NERO DVD Speed and download the newest version. I mentioned that Jitter is very important and could cause coasters. It is also important to utilize the entire disk when determining burn quality.
There are many topics about PIE and PIF, some folks dont even bother because different burners read and decrypt ECC (Error Corection) differently (giving you different results with different burners). I believe PIF ECC for anything above 2.4x speed will be measured using 8 ECC per 4 blocks, with a max of 32 PIF. Some folks say to stay less than 16 PIF for certain burners such as the BENQ 1620.
The best advice I can give you is to research, read and read some more. There are many Threads covering how to read scans.
Good luck and happy burning.