"and I noticed pixelation a bit on one scene of the movie"
Personnaly (but don't take it for granted...) I think it's pure myth to think that burning speed has anything to do with pixelation.
Bad burns will produce reading errors (block noise, freezing, skipping) but pixelation is IMO an issue with compression, not burning.
Pixelation and block noise are visually similar but rather different in magnitude. And as you mention it as being "slight", I'm sure it's not block noise you're experiencing...
The pixelation may even have been present on the original media (or broadcast). Have you checked?
It's rather frequent from poor transferts, actually. I just finished copying some Buffy episodes from Season 3 and they're visually awful. I though it was an issue with the Shrink process, but then I took a look at the original DVDs and... discovered that all the flaws were there right from the start!!! LOL :Z
Oh I use the same Ridiscs G04 as Yoda, and burn them at 4x on my Pioneer 109 with Decrypter, playback is fine on both my standalone players (an old Pioneer DV-535 and a JVC DR-M10).