I could be wrong but I believe I've seen this question in another forum about another storage device
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My experience is with the DNS-323, the first of D-Link's 2-drive NAS units rather than this one, and according to DLink the difference between the two is that one has a USB print server and the other doesn't, so my experience should be relevant as far as reliability goes.
It's going to depend on how stable (or reliable) your wireless network is. If you have a robust wireless network, you'll be able to use the NAS over it with no difficulty, albiet somewhat slowly - on the other hand, if your wireless network is ****e to errors and disconnects, you'll wish you never bought it.
Now - as a disclaimer - the above holds true (in my experience) for any network storage device regardless of brand or model, for the most part I've been very happy with my DLink DNS-323 and my use of it over wireless, whilst not very frequent (due to the speed) has been problem free
ever since I replaced the Intel 2100a wireless card that appeared to work quite well but in fact had an extremely high receive error rate.
Why am I pointing this out?
Because a wireless network that allows you to surf the net with no problem, may not allow you to use a network storage device (this or any other one) without crashing.
If you're going to use networked storage, your network is going to be the prime factor in determining the general usability of the storage device.