New WD hard drives for MP. Green or RE4?

[Transporteur]

Hi there

I'm getting pretty close to the magic 50% usage limit of my internal data array, which consists of two 1TB WD Blacks (Raid 0).

Instead of adding a third and fourth 1TB drive to the Raid 0 (which would dramatically increase vulnerability of that type of array) I thought about replacing the 1TB drives with 2TB drives.

The question is now which one's to get.
2TB drives are available as Black, RE4 or Green editions.
My current 1TB drives are Blacks and I don't want to get them again because they are horribly loud and here in Europe they are even more expensive than the Raid Edition drives.

So I'm basically down to RE4 or Green. I've got both of such drives, a 500GB Green and some 500GB RE in my server.
The Green is very quiet (which is good ), but I've got no idea how loud the RE are because my server drowns them.

I've read some user comments about the 2TB RE4 and people say that they are extremely loud.

So, yeah, why not just buy the Greens? I've got some thoughts about their speed in a Raid0 array.
My current array of Blacks makes exactly 200MB/s writing, which is pretty good I guess (more is always better but that value is fine for me) and I don't want to loose that speed.

Any thoughts about the 2TB Greens or RE4s?
I'd like to have some recommendations before buying those drives because they are still pretty expensive