Wider is better.
Most people buy CD-ROMs as they would buy a floppy drive. As long as it works and has a high number next to the "X" it's good enough for the average Joe. This probably happened somewhere after the speed ratings went into the double-digit area; nowadays drives tout speed ratings of 32X, 40X and more recently 72X. They keep on getting faster but nobody's really complaining; of course, some of them sound more like little jet engines than something that belongs in a computer.
Many drives rarely live up to the speed rating at which they are advertised. Most manufacturers only post the maximum speed the drive will attain, without a mention of how long the drive will sustain this maximum speed, or how the drive performs in non-optimal situations. Plextor seems to be one of the few manufacturers that has broken with this norm. Plextor labels its drives with two numbers, one denotes the maximum performance the other number denotes the minimum. In the case of the Plextor 40X UW SCSI, the documentation states that the drive is rated as a 40X/17X.
To someone unfamiliar with the CD-ROM industry, the Plextor name might not illicit any awe. Plextor is well known for making some of the very best SCSI and IDE CDROMs available. Plextor doesn't really target the home user since most home computers don't contain SCSI setups, and as a result brand isn't too well known to the home enthusiast.
If one does the research, you will find that Plextor makes the drives that are used in large CD-ROM servers. Most of the guys with the healthy monitor glow will generally recommend Plextor. These drives have won awards from various magazines, and I too have been recommending Plextor drives to friends (Sarju has been working on his monitor tan as of late -Ed).
Our review unit was not provided by Plextor, but rather purchased by yours truly. I did quite a bit of research before purchasing this drive, and looking back I think I could have done more. I could have paid a little more attention to the SCSI interface than the drive itself. But onward and forward I say, not backward or downward. Would I still recommend this drive after owning it? Read on and find out!.