I think it will resolve itself by a market -- this "NAS" are just overpriced, otherwise it's normal low-end solution for lazy user. I am also quit lazy, but after one experience with Buffalo Terastation I prefer to use MediaSonic enclosure connected to my server, similarly as other user adviced...
When it will be 800$ including 4x 3TB HDDs, than it will make a bit sense. Now it's a normal rip-off, which is actually quit normal and respected business nowadays.
If you look on a typical supemarket shelves, you can easy see that most products are even not intended to be usefull not for consumer but just designed to make a money for seller. Normally cinsumer doesn't like to buy this goods and that is why there exist multi-billion dollar marketing industry, to make you buy different "brand" trash...
In IT you can at least test yourself...
So just decide yourself, not trust ads at all and make some research before buying -- and you will be reasonably safe to get what you need, not what is marketed...