IMHO, I think those burns are very similar and they are pretty good for -R media and well within specs for a good burn. The first scan, you can discount the single spike, which puts both the PI and PIF graphs equal. PIF's are far more important than PI values, and PIF never get above 2, while the PI max is around 100, which is also well within specs. I agree that better burns can be had with better media, I just wanted to input that these burns weren't so bad...I bet they both play/read OK.
PS, you can remove the single spikes to view the rest of the graph by right-clicking on each graph and choose 'delete highest value'.