Data Transfer Performance
It's easy to see that the drives running at 5,400 rpm have difficulties exceeding 30 MB/s. Both the Maxtor 536DX and WD's 600AB fail this to surpass this number, Seagate's U6 series (ST360020A) provides 31,600 kB/s.
Disk Access Time
HD Tach does not only return seek time results like many other benchmark programs, but the full access time that consists of seek time, plus head positioning, plus rotational latency (that's the time you have to wait until the right sector passes the read/write heads). The Maxtor drive is clearly faster than the Seagate and Western Digital drives.