External HD advice requested

What are you using this drive for anyway? Occasional backup? Mobile storage? This'll kinda dictate what kind of drive you should be looking at.

Even firewire 400's going to be faster than USB, so there is a speed benefit. Also, a firewire connection will easily handle the power required by an external 2.5" drive, so no extra power cables are needed if you want to go the portable drive route. Extra power may be needed for portable USB drives, meaning you need an extra cable and an extra USB port or wall socket.

I don't know if you should bother with the NAS. It'll end up being much more expensive (3-4x or more) than a single drive. I'm assuming you're talking about using RAID 1 to mirror the two drives in case one of them fails (using RAID 0 would be idiotic). If you REALLY want to spend that much money, go for it, but I doubt you'll need that second drive as long as you get a high-quality drive. RAID 1 can be useful in some circumstances, but I don't think it'd be worth it for you.

That being said, I'd suggest just getting another WD. Personally I've had very good experience with them. Take a look at their warranty policy and grab one that had 3 or 5 years worth of coverage. http://support.wdc.com/warranty/poli...policy?lang=en

Another idea is to buy an external enclosure and buy a drive to put in it. I personally like this approach because of its flexibility. You can shop around for an enclosure that has a good reputation and the interfaces you want and mate it with a hard drive with a good record and a good warranty. Depending on what you get and where you buy it, you may be able to save some money while you're at it. Example: The WD external drives have warranties ranging from 1 year to 5 years, depending on what you buy. All WD internal drives have at least a 3 year warranty, even the green (cheap) ones.

I had a 500GB WD MyBook go bad as well, but it turned out that the 500GB SATA drive inside was still OK. I splurged on a Macally G-S350SUAB enclosure, it has FW400 and FW800 ports. Works fine.