MBP 7200 vs 5400 RPM Battery Life

I've been seeing random posts from different people saying conflicting things about the three hardrive options in the santa rosa macbook pro. My question is whether or not there is a significant difference in battery life between the 160gb 7,200 rpm and 5,400 rpm hard drives? Also, is there a significant heat difference?

One answer I saw was that since the 7,200 rpm runs faster it produces more heat and power, but a rebuttal to that was since the 7,200 rpm needs less time to find data it balances out?

Thanks.

 

7200rpm will consume slightly more power and more heat due to its faster spindle speed. But of course the speed will balance out everything.

5400rpm drives is a compromise between 4200rpm (speed) and 7200rpm (power). (erm, I don't think that there is a significant speed difference between 5400rpm and 7200rpm, so i'd go for 5400rpm.)

 

This my understanding, but someone can correct me if I'm wrong.

For regular activities like web browsing and word, there should be minimal difference. However, when transferring a huge file, the 7200 has the speed at the cost of battery life, but you'd probably be plugged in when doing that anyway.

 

Thanks guys, if there wasnt a 4-6 weeks waiting time on the 7200, I'd get it, but I don't know if its worth it.