What model WD drives do you use for your redundancy - Black/Green/Blue?
Hmmm...had to go and check, as I didn't recall offhand. I have a mix of Blue from 2008* and Black from 2010. I also have a 2.5" Green for non-critical portable backup of my laptop, though I don't use it much anymore since I'm not traveling for work much these days.
* As an aside, 2008 was one of the few times I took advantage of WD's warranty exchange policy. Two of the Blue HDDs I bought in 2007 both bombed within the first year, within days of one another. Turns out I got caught up in a bad production run. Thankfully, they didn't die suddenly, and I was able to transfer all my data when the replacements arrived...before returning the originals. But even had they died suddenly, I would've been safe -- the two Blues weren't part of the same redundant pair, but rather one each from two different pairs. Thankfully, at some point before 2008 I got nervous about getting hosed by a bad production run -- if memory serves, due to a recommendation from someone here on TS -- and started using Blue and Black in my pairs, rather than 2 Blues from the same manufacturing time window. Food for thought if you're building up your redundancy plan.
Also, at the time of the two Blue failures, I wasn't diligently using an off-site backup. I can tell you, I found it nerve-wracking to know all my critical data existed in only a
single place for the ~2 days it took for my replacements to arrive. Needless to say, it motivated me to start performing more diligent off-site backups!
That said, don't let the bad production run turn you off off WD. Every HDD manufacturer has had issues at one point or another. The key -- regardless of HDD manufacturer -- is developing a redundancy strategy that won't come back to bite you in the event of a problem.