Which advantage do 15k RPM drives provide over 10k drives?

Higher seek time would be a performance disadvantage, not an advantage - seek time is the duration needed to physically move the read/write head to the correct track, and 15k drives do not inherently reduce or benefit from a higher seek time.

Duty cycle describes the rated workload capacity of a drive, and 15k drives do not provide a higher duty cycle - they often generate more heat, which can result in equal or more conservative duty cycle ratings.

MTBF (Mean Time Between Failures) is not improved by higher RPM - the increased mechanical stress and heat produced by 15k drives can lead to MTBF values comparable to or lower than those of 10k drives.

Rotational latency is inversely proportional to spindle speed - a 15,000 RPM drive completes one revolution in approximately 4 ms, yielding an average rotational latency of about 2 ms, compared to roughly 3 ms average latency for a 10,000 RPM drive. This reduction in wait time for the correct sector to pass under the read/write head improves random I/O response times, which is the primary performance advantage of 15k drives over 10k drives.