I dont know what you want in answers ??? in the end only you have your media and hardware so even if I have the same I could only give you some idea of what to expect, as everything in my systems are different, even down to the age and life of the media.
I dont see where anyone said that there would be a problem at 4x and I said that the only difference was that the jitter gets better at lower speed i.e. the burn is better.
'Drage' said that it is "The media itself is true multi-speed" so that gives me the impression that he thinks it will be fine at any speed. What speeds does your drive work best at ? I would think its best to work from there and see.
My drive is not the same, but I would have thought that it is quite a close match, and the media is up there with the best you can get, you are just going to have to try it for yourself and see... its the only way you will get the data you want.