Haven't got one, but ive heard bad news regarding cooling on them. As they have no fan etc, it seems that the higher capacity harddrives can get really hot in them (maybe too hot)
Also, again from what i've read, there not like normal NAS devices which you simply connect to your network and are able to browse the network shares. For the netgear storage central you have to install drivers on the OS and then it see's it as a drive letter. This could make a difference depending on how your using it. i.e. my NAS gets accessed by quite a few people on our wireless network, having them install software just to get a few small files, is not going to bode well......Of course i could set up a file share from my computer, but that kinda defeats the purpose of it.
