In my experience, hitachi drives use up more power then their specs states.
I had a Hitachi DK23DA-40F 40gig FDB 4200rpm drive, and I upgraded to a IBM 40gnx 40gig 5400rpm drive.
According to both specs, the IBM drive should use up more power and produce more heat. (about 10 to 15 percent)
but in my testing under the same circumstances, I always get about 20 to 30 minutes longer battery life with the IBM drive. (all else being the same).
This is on a Compaq EVO N600c laptop. Also the bottom of the machine runs really hot when using the hitachi drive, to the point where your hands will hurt if you touch it for more then 10 seconds. With the IBM drive, it is barely warm to the touch.
Performance wise, Sandra disk benchmark reports a 40% jump in performance.
I can feel a significant performance improvement. Windows and application start times are about 20% faster with the IBM.
I have not used the toshiba drive so I can't comment about that. But in the past, I preferred toshiba 4200rpm drives to IBM 4200rpm drives because they just felt faster to me (no real benchmarks done to back that up, just a personal feeling).