I think you replied out of context. My reply was to someone who was claiming that there was no rational reason to use SCSI under any but the rarest circumstances. My claim was that there are some very good reasons that SCSI should be used in various situations, not that everyone should use it for everything!
With UDMA CPU ussage for IDE has been cut down to the point where it doesn't noticably slow down the system.
Yep, though the CPU usage is still higher than an intelligent SCSI controller, you won't see drag when copying a file on your ATA system anymore. Now, try opening multiple programs and doing multiple simultaneous data transfers, while swapping to the same disk. Hint: Just because YOU haven't been disappointed with IDE, doesn't mean that it doesn't have its shortcomings.
Also IDE drives are NOT "throwaway" quality. IDE drive manufacturers have to maintain very low failure rates because of the razor thin margins they live on (as low as $1 a drive).
Note that this discussion is about DVD drives, not hard drives. In any case, ATA drives do fail in volumes more than SCSI disks, due to at least 2 common reasons: stress due to desktop power management, and more recently electrical anomalies caused by the popular use of rounded ATA cables. ATA disks are also rushed to market compared to SCSI disks, and occasionally suffer from severe issues, like the Deskstar 75GXP series, the WDC 20AA series, and the recent Fujitsu problem. Because of the "razor-thin" margins that you quote, these manufacturers are also quite unwilling to service their customers besides what is absolutely required of them. I'm not saying the support for SCSI disks is any better, but IDE disks aren't the utopia you present them to be.
As for price, last I checked the price per GB of SCSI drives was 4-5x that of IDE.
Yep. If the point that you're trying to prove is that IDE drives are more cost-effective for mass storage, then this is a good point. However, it still does not address reliability and performance concerns.
No power user who isn't either sunning a server or a flaming elitist (hint) would use SCSI on the desktop.
Nice jab, but this is again another broad and baseless statement. Why would someone who would derive a benefit in the work from the strengths of SCSI decide not to use it? That would not be a rational decision. SCSI is an important component of my (mixed) system, because I was being limited by the drawbacks of IDE in personal media production. Does this really qualify as grounds for an ad-hominem attack to label me an elitist?
I've never had any such hassles with IDE.
Personal anecdotes don't count for a whole lot. There are plenty of people on tons of newsgroups and web forums that would disagree with you. If we really want to gauge which is the more useful interface, a poll is the correct option.