Or maybe not.
I got me a SmartStor NS4300N and two 750GB hard drives last week, after contemplating the idea of a home NAS device for a long time. I bought the device under the premise that its noise level remains under 40dBa, which, sadly, was hardly the case.
This device is equipped with one of the most annoying power supply units I've ever encountered, emitting a high-pitched noise which can drive me nuts. Now, most normal people can learn to ignore such background noises and learn to live with them; I, however, am quite insane when it comes to noise damping, and can go to extremely extreme extremes (read it again; it makes sense) in order to avoid such noises.
However, having spent over 500$ on this unit, and additional 300$ per hard drive, I was not going to give up.
First order of business was to open the device, which has proven to be quite a formidable task due to the fact that Promise have decided to use a rare breed of star-headed screwes for the enclosure. Having customely built a screwdriver that can fit in the screws' heads, I proceeded to open the enclosure.
Luckily, the NS4300N is composed of standard part, including an 80mm system fan (a slim form-factor fan, though) which was also quite noisy and an mATX 200W PSU with the forementioned noisy-as-fuck 40mm fan and a standard 24pin ATX connector.
After practically taking the device totally apart, I've managed to remove the dreadful PSU and replace it with a picoPSU I once bought for my HTPC (which it never managed to power up) and replace the system fan with a 80x80x25mm Thermaltake fan I had lying around, thru a Zalman Fan Mate 2 (which required some cutting and re-attaching of wires due to the non-standard fan connector Promise has chosen to employ).
Having re-assembled the enclosure and mounting the drives, I hopefully turned the device on and to my surprise, it actually works!
The picoPSU, tiny bastard that it is, managed to supply enough juice to spin up two WDC7500AAKS drives (which consume circa 13W during spinup) and start the NS4300N up successfully, even though I'm only feeding it using a 5A power block.
Bottom line? I fully recommend the NS4300N if you have an isolated room you can store it in, or if you're as technically-minded as I am and can afford to spend the time and money on modding the device.