Thanks for advise. Green looks like a good match, however, for some reason on Tomshardware forum ppl have complained that Green drives are actually LESS reliable and have advised against it... any feedback there?
That's a topic that has been raised several times, also here on SPCR. I do not know if the "myth" is correct or not. I can say, however, that it has the same warranty as a Blue, and that my WD green 500 GB still functions well, and I've probably messed around with it trying to suspend the drive.
Also, how does the Green performance compare to Blue?
In general: worse. But newer drives tends to be faster than old drives (new technology, platter density), so my guess would be that a new green drive would not be far off your Blue 500 GB, performance-wise. Benchmarks or other people will give you the answer on this one.
for some reason the 1 TB BLACK drive has reviewed much worse (acoustically) than 2TB... any reason for that? have they changed anything specific?
As performance increases from one generation to another, the acoustics increase too. The 1 TB black is from end 2008/start 2009 (using 333GB/platter) whild the new 2 TB is from october 2010 (using 500 GB/platter). New generation = better acoustics (usually).
With your demands, and your acoustic requirements, a 1 TB blue would probably suffice. Or maybe a Samsung F3 1 TB, which has been widely praised:http://techreport.com/articles.x/19330
The Blue is apparently quiet enough for you and the performance is definitely good enough. After all, they are meant as system drives.
Looking solely at your needs, however, I'd say a WD green would suffice. You could save a few bucks, it's much more quiet, and the performance is meant for your needs. The Blacks should be out of your question, since the price premium isn't worth the extra 2 years of warranty. Just think how much harddrives can improve in 2 years. The acoustics are not that great neither.