BenQ 8x DVD+R media is generally DAXON AZ2, and it's utter CRAP. Do not buy it. Funniest of all, the 1620 firmwares (B7T9 and on, AFAIK, and probably some earlier ones too) think that it's 16x capable media!! If you get a single good disc at that speed (ie, 96 or better CD-DVD Speed quality test score) then you have both a magical burner and an unusual example of BenQ media.
I've gone through over 200 of the damned things, from 5 different spindles purchased from different stores (in a 30 mile radius, admittedly) and I ended up exchanging the failures (about 30%). Thanks to Future Shop for their excellent 30-day guarantee.
While browsing these forums, I thought (after looking at the scans posted) that my burners just sucked (have 3 BenQ 1620s). I was totally, completely, 100% wrong. My new Fujis (TY T02) are perfect. Even the shittiest burn at 16x overspeed is better than the best DAXON AZ2 disc I'd previously done at 4x, 8x, or any speed.
I'd never buy BenQ again. Go with something that says "Made in Japan" on the side of it, or anything by Verbatim. I can't tell you how much I hate BenQ media, it's wasted so much of my time.