Results for the Atlas III were disappointing. The drive lagged competition (the Seagate Barracuda 9LP and even the IBM Ultrastar 9ES) in WinBench 98 figures by margins of 15-20%! ThreadMark results were a bit better- the Atlas III placed just a bit behind the Barracuda 9LP here and performed better than the Deskstar 9ES (although to be fair, the 9ES is marketed as an entry-level drive, supposedly not the same class as the Atlas).
The Atlas had the unenviable position of being the drive I tested and used after Seagate's Cheetah 9LP. This, of course, highlighted the drive's sluggish performance. It did, however, also make the Atlas III seem whisper quiet . Ok, well, not quite. There -is- a noticable whine, not nearly as loud as the Cheetah's. It's probably on par with that of the Barracuda's. Actuator/head movement, however, was quieter. You can still tell it's a SCSI drive, but its not as loud as the Seagate drives. The drive was cool to the touch when used with active cooling; one could probably use it without drive fans in a well-ventilated case.
It's hard to recommend the Atlas III. The Seagate Barracuda, available at the same price, outperforms the unit by all measures, its only drawback being a louder seek noise. IBM's 9LP (not yet tested by SR, though it's planned) may also offer better price/performance, perhaps with quieter/cooler operation. In fact, I wouldn't be surprised if Quantum's own Ultra2 SCSI Viking II (testing also planned) performed better, at a significantly lower price to boot. Prospective Atlas III customer's would do themselves some good to consider these three alternatives before making the leap.