Well, that's the thing. Here, a 3TB WD Green drive is currently CAD$130. The 4TB Seagate is CAD$190. The 4TB WD Black is around CAD$300 by comparison. The problem with my MythTV box is that it has only 3 internal drive bays, which are already filled with 3TB drives.

Actually, I've installed the 4TB into that box as a fourth drive, by suspending it over top of the motherboard/RAM area (horizontal case). Some trickery was required.

Edit: I expect prices to remain fairly constant until WD releases their own "Green" (and "Red") 4TB drives this summer. If the Seagate is still behaving itself then, I might buy a few more of them once prices come down more. Note that these drives are equivalent to the WD "Red" series (5900rpm, TLER, etc..).

Cheers