I can tell you I've had 4 of the Western Digital 1TB "Green" Caviars pass through my hands, 1 was DOA & 1 crapped out after 5 months. Had to RMA them (the DOA one to Newegg, the other to WD) which added about $18 to the cost of the 2 functioning (knock wood) ones I have now.
Both failed examples were WD10EACS, not the currently available WD10EADS, but I think the only difference is the DS has a 32 meg cache, the CS, 16. Unlikely this had anything to do with the failures I experienced.
I use them as bulk storage, have never booted from them. Nor would I, given the unreliability I've experienced.