Uh...4x dvd burners are not the same as 4x cdrws. A 4x dvd burner will write a lot faster than a 4x cdrw could ever do.
Example:
Some specs from
www.cdrinfo.com on one of the Pioneer DVD writers.
DVD-R: 2X-CLV (2.770 MB/s), 1X-CLV (1.385 MB/s)
DVD-RW (both v1.0/1.1): 1X-CLV (1.385 MB/s)
CD-R: 8X-CLV (1.20 MB/s), 4X-CLV (0.60 MB/s)
CD-RW: 4X-CLV (0.60MB/s)
Compare the 2X recording speed of the DVD-R to the 8X recording speed of the CD-R. Notice the little difference there?
Also from the same review: "At 1X writing speed, a full DVD-R/W will need around 63-64mins to finish and with 2X writing speed (DVD-R only), you will need half that time, only 35mins." 35 minutes to record 4.4 gigs. I want to see a 2X cdrw do that!
EDIT: 2 AM and I'm bored so what the hey! I'll post some more stuff.