At the risk of this getting thread getting moved to a different forum tinkapace I'd have to say that if your looking for a 'budget' disc try any that use Ritek dye.
I've only just upgraded from a Pioneer 104 (x2 speed) to a 105 (x4 speed) and have had very few problems with discs using Ritek dye.
Having said that, I'm just trying out some o1ne x4 discs that have lead data dye. 3 out of the first 5 were coasters until I updated my firmware and the last few seem OK but I'm still reserving judgment on them!
If you really want to be sure shell out a bit more cash and get some quality branded media such as the Pioneer stuff itself!!