I'm playing the US version from disc this time because my HD is louder then the Wii's optical drive.
Barely notice the difference most of the time from when I played the PAL version.
If your Wii has problem reading dual layer games though I can sympathize.
Well, in the case of Xenoblade, you aren't actually experiencing load times super often anyway, so I suppose it's not a major draw for it in particular. I use a 16GB SDHC card through a USB card reader for games, though, so it's totally 100% silent for me.