I don't know about the spinning disks - it could be about where the main files are located. If they're towards the edge, then the disk spins faster (I think) in order to preserve the data rate. I'm not 100% sure on this point. There's probably a more technical answer to do with the effects of downsampling. I really don't know!

But on your other question, well lots of us are buying DVRs and we've found DVD-Rs at £3.75 + VAT from SVP. Can't seeany other way of proceeding with the bulk of games coming out on DVD. Or I could spend my life ripping DVDs - nah.