in the end it depends on the individual drives and how they're being used.
Bottom line...very little if any difference especially in the intended use.
The only thing is you might want to use the drive as a primary in another system... so if the difference isn't too great, it might be worth a few bucks long term. Take a look at NEWEGG.COM ... they've got a good selection of the latest drives with full warranties...usually 3 or some with 5 years and good prices.
You can do some further reading at Storagereview.com
I'm looking to buy a SATA hard drive soon.
I'm just wondering as to how much of a performance jump would a 16 MB cache give me as compared to a 8 MB cache.
If it really matters, I intend to mostly use this drive as my secondary drive to access my files (Office, music, movies, pictures, etc.) and keep all program installations on my primary drive.