I recently bought 3 Verbatim 16x DVD+R 100 spindles. Two of them were Prodisc and one is CMC, as discussed here: http://www.cdrlabs.com/phpBB/viewtopic.php?t=22781
I have tested both Prodisc and CMC at 16x, 12x, and 8x using a Lite-On SOHW-1693S KB0B. The results are posted here: http://www.cdrlabs.com/phpBB/viewtopic.php?t=22863
When I view the results I am thinking the CMC are good right up the 16x on my burner and that the Prodisc are more suited for 8x.
For both Prodisc and CMC my burner seems to have a speed wobble when it reaches 15x. I am thinking that is more of a burner issue than a media one.
Here are examples: