Copying files from a CD via Windows Exp. Vs ISO file from IMGBURN

I tried to get the mp3's from a CD (approx 5 folders 200 songs) to a USB attached portable mp3 player.
My first attempt, drag and drop from the folders to the mp3 player in Windows Explorer was terrible.
The progress bar kept jumping from a 5 - 20 minutes estimate. All kinds of weird noises coming from the CD drive
as it sped up/slowed down.

I quickly cancelled, and tried to copy the files using the same method to a folder on the desktop instead of the USB device.
Same problem. Cancelled that too.

Next attempt, I used IMGBURN to create an ISO image on the HDD (about 2 minutes), 7z to extract the songs to their
original folder/file structure (2 mins), and 5 minutes to copy to the USB device. More steps but much
quicker and cleaner.

My original thought re: the earlier attempts was that the drive was having trouble reading the media; but the creation
of the ISO file shows this was not the case. Perhaps when you use Windows Explorer the read order is
indeterminate and the CD laser is jumping about all over the place, Vs. a strict sector by sector read when creating the
ISO?