For a 7200rpm drive, the Seagate is commendably quiet. The high-pitched whine that often accompanies ball bearings and high spindle speeds was nonexistent. The drive's noise level while seeking is a bit higher than the IBM drives, however. Even so, the noise was nothing compared to the churning one hears when using a Barracuda or Cheetah :).
Speaking of the Cheetah, the Medalist Pro seemed to match it in one area: Heat. After the initial installation and first run of WinBench, the drive was amazingly hot. I'd venture to say that no other 7200rpm SCSI drive that I've used generated as much heat as this ATA newcomer. The results of the first pass at WinBench were notably poor, probably due to slow seek times from the drive exceeding its rated work temperature of 55 degrees Celsius. Once placed in the drive cooler that I normally use with my Cheetah, the drive ran much cooler and posted the results listed above.
Seagate's Medalist Pro ST39140A undeniably raises the bar for performance in the ATA drive arena. Blazing speed combined with quiet operation make the unit a standout. Unfortunately, heat seems to be a major concern. I consider a drive cooler mandatory for this drive, a first in the ATA realm, not only to prevent premature drive failure but also to achieve maximum performance. If you already suffer from heat problems (anyone overlocking out there??), you may be better off with another unit. If, however, your system is well ventilated, the ST39140A is second to none.