What I want to know is if the load cycles is a real concern or are we paranoid? I will run a test as I have the same drive. My drive clicks and it is always active, unlike the stock 750 GB Toshiba 5400 HDD. Also, I repaired disk permissions, as my boot up time decreased 3 fold since I installed the 750 GB WD.
EDIT: I am testing the battery life for the first time with the WD HDD. If I do not like this drive, then I will not hesitate to reinstall the stock HDD and use this drive as a scratch disk etc...
If your load cycles are increasing at a rate that is too high, then yes, it's something to worry about. With 300000 as the rated number, just do the math and figure out how long it would take to reach 300k. If it's more than 4-5 years, I'd just let it keep adding cycles since most people won't be using the same HDD for over 4 years anyway.