based on the spec sheet provided, I am speculating,
7k60 vs 7200.1
7k60 has Areal density(AR) 50Gb/sq inch
7200.1 has AR 80Gb/sq inch
even by the mediocre performance found on most seagate drive(longer average seek time, AAT), 7200.1 will definately faster with higher substained transfer rate(porportional to Max media transfer rate,MMTR)..
7k60 Max media transfer rate(MMTR) 512Mb/s
7200.1 MMTR 645Mb/s (error +- 10%. A theoretical value based on AD and 7k60 MMTR. since 7200.1 has no datasheet right now.)
takes hitachi 7k60 60G vs seagate 7200.1 100G, they are both 4 head with 2 platters and rotating 7200 rpm, the heat generated with be about the same.
i am sure Seagate 7200.1 will be more expensive when available.
ds23 vs 7k60:
dk23FB-60 has AD 68Gb/sq inch and
7k60 has AD 50Gb/sq inch but it rotates 7200rpm so
based on the figures, you will feel the differnce from dk23 to 7k60, just like what the dell forum regular said.
in conclusion, based on datasheet speculation,
7k60 is definitely faster than dk23 but less than the % increase from 5400 to 7200(or 33%)
7200.1 maybe 20 % faster than 7k60