PIO4 is 16Mb/sec and faster than any burner made. It makes no performance difference which you have. On any MB made in the past few years a PIO4 drive will not slow a UDMA/ATA 66 or 100 HD on the same channel. There are important considerations to make in the purchase of a burner and I donít think that whether it is PIO or UDMA is significant.
Just look at the CD-RW labels in the store. Many are 10X now.
If you can keep your head while others around you are losing theirs, then there is something you don't know