Wow, Chas! Nice media chart! I've bookmarked it and will point others who may be interested to it. I'm glad there's a lot of people like you in this forum who provide such helpful information. (thumbs up)
I'm surprised they aren't better on your Pioneer DVR-109, as my y000t02-00 burn well on my DVR-108, although I've only burned them at their rated speed. However, I got the same beautiful graph as in my Plextor 716a at the same speed. My Pioneer does better on jitter than the Plextor, though.