This comparison between the mentioned drives is somewhat apples to oranges.
It seems to me, that hard drive use cases fall pretty often in the following categories:
SSD units; they are all silent, so you don't really need to review them
[list="expensive single hdd system"]
2.5" HDD units; these need reviews, because there are large differences in noise between them
[list="cheap single hdd system"]
3.5" HDD 0GB-333GB size. cheapest option, modest storage space, single platter solution is next in silence to 2.5" hard drives, but can have HIGH performance. need reviews
3.5" HDD 333GB-640GB size, 1-8 units in single system. This size group has most storage per money, so as long as you can connect them all, it's the cheapest way to achieve several TB of storage. need reviews
It seems to me that 2 500GB drives would often be better than a single TB drive, because they have a hefty premium in price. But if you want to minimize the number of hard drives, or keep the number under some hard limit (so you don't have to buy a larger case or extra controller cards), you might want to pay more per GB. Need reviews too, but imo the 2-platter category is more important
I can't figure much other uses for a TB drive than
a) single drive system with almost 1 TB of required storage space. it also needs to be fast, because it's your system disk, so WD GP is not so good.
b) huge storage system; WD GP is a pretty good option
c) commercial dataserver -> servers in a server room -> not spcr stuff
I guess what I'm trying to ask is this: If you need a bit less than 1TB of storage inside your computer, but you also want it to be fast, what would be the best combinations of drives with different budgets?
Extreme budget: SSD all the way
Almost extreme budget: SSD system/app disk, WD GP storage disk
Dunno what budget: Any option that I miss here?
Medium budget: single TB drive, but WD GP is too slow, so what is best?
Cheapest: 2 * 500GB, but is this quieter or less quiet than 1TB drive?
my general purpose desktop system: HP LP3065 30" LCD 2560x1600 pixels, Q9450, 8GB DDR2 ECC 800MHz, EVGA 460GTX 1GB SC (OC@800MHz/2000MHz), WD Velociraptor 300GB, Samsung 2TB, Gigabyte EX38-DS4, Antec P182b, Corsair VX450, Thermalright Ultra 120 Extreme, Scythe S-Flex fan, <90W AC idle, 200W AC gaming