I'd had it in my mind that a drive with more than 3 platters would be statistically less reliable. Is that the case for modern drives? Would then this likely be a more reliable 3TB drive? That's assuming the very high platter density isn't itself unreliable.

(I'm not rushing out to buy any drives these days. The shortages will presumably be with us for some number of months.)

I had four of these drives in use and they seem very noisy to me. In fact when I shutdown the computer they make this troubling whining noise. In use they sound a little like popcorn popper.

One of the four I had to RMA it had unrecoverable bad sectors within a week of use.

I am comparing this drive to:
Samsung F4 2TB, WD AVG 3TB, WD Green 2TB drives which are more silent in my systems.

Hmmm. Hard to reconcile that with SPCR statement that "The Barracuda 3TB was easily the quietest high capacity 7200 RPM drive we've tested, measuring 16 dBA@1m when idle and 16~17 dBA@1m when seeking. It emitted a very soft hum without so much as a hint of whine and the seeks were almost unnoticeable."

Possibly I have defective drives since the second of 4 drives has now failed with a unrecoverable sector.
This is after I performed a full zero fill of the drive a week earlier.

With a 50% failure rate for me I am not very happy with these drives, regardless of how they sound.

Drives with a few bad sectors aren't failed.

You might be getting inter-modulation noises. The case can act like a guitar body and 'amplify' the resonances.

If they are in a RAID array then they all seek at the same time and you can get some very annoying noises.

Modern HDD's have no bad sectors visible on the user side. Any surface flaws are automatically remapped to the spare area.

You can see bad sector counts with SMART and some models require you to use a special utility to reallocate the sectors (as of a few years ago anyway).

Bad sectors on a factory fresh drive are invisible to the user. They don't cause errors. Any errors are a result of either a soft (non-repeatable) write error or a new permanently bad sector.

Errors should be very rare on new drives. You generally only see errors on old drives which are failing. On the other hand, 3TB is a lot of data and the more data you write, the greater the chance of an error.

Don't quote me on this (verify for yourself) but this isn't what Google found. I think they got a slight bathtube effect.
I also got bad sectors on newish drives (though not often).

Just to clarify I had non recoverable bad sectors on two out of five drives, now that two of them have been replaced.
Non recoverable bad sectors are when the drive has a bad sector that cannot be marked as bad and spare used to replace it.

I am not using these in raid.

The sound I hear with the new drives is I guess when it is parking the heads during no use or at power off, it is very noticeable.

I use these in HTPC or USB 3.0 external enclosure, so they are low usage drives, which makes the failure rate of 2 out of 5 seem a even worse. The last drive received was manufactured in China, the previous 4 from Thailand so maybe that will make a difference.

I bought the 2TB version of this (ST2000DM001) after reading this review. The noise (which is apparently due to head parking) is very obvious, as pointed out by numerous others on the internet.

This thing does not make it as a silent PC drive. A warning needs to be placed at the end of the review instead of a gold recommendation.

Add: Windows 7, AHCI and newest firmware (CC4H). China made in Jun '12

Add2: hdparm managed to make it shut up, at least so far I only heard something once.

I've just bought the 2Tb version and I'm getting the chirping, I can live with it if the drive isn't going to die because of it, I find it worrying nonetheless.

Newegg has this on sale today. I was going to use my older WD 640GB Blue in a new build (secondary drive behind a SSD). Can I compare the noise level tests for that test http://www.silentpcreview.com/article847-page3.html, at that time to the current tests?

The noise floor of the testing area back then was 17 dBA. Now, it's 10-11 dBA and some of the equipment is different/better. So, the seek noise of 22 dBA for the WD 640 Blue back then would probably translate to something slightly less than 22 dBA if tested today.

Empirically, it is a very quiet 7200rpm drive so I wouldn't worry. It has a low hum which is quite hard to hear. No buzzing or grinding noises. The only drive I would consider getting instead is the Caviar Red but it is usually more expensive.