I bought this device for a bit under $200. Cheapest I could find it. Sold as the Raidon/Stardom SL3620-2S-LB2.
I had to reflash the bios with the newest firmware twice to get it to detect my two 1TB drives properly. Once that was resolved it worked great. Interface is very easy (I'm biased as RAID and Security are two of my daily tasks) and works well. It is simple looking though, but I prefer that to flashy interfaces like D-Link. I don't have the bittorrent feature even though it says I should. Also, they are NOT hot swappable drives. The box says they are, the manual says in no uncertain terms not to do it or you risk loosing your data.
From what I can tell, it's based on a SIL4726 controller which is about middle of the road for consumer devices.
I can only write to it at about 7-8MB. Reads are a little faster (RAID-1). I can safely stream 720p content, haven't tried 1080i yet.
Overall, compared to other NAS devices, I'm pleased with it. It cost considerably less than most comprable devices and seems to run very stable and cool.
I just with the designers would get the firmware right. Or that someone would come out with a better os to flash onto it!
On a side note, the AMS Venus T5 has the same chipset, it's esata and works like crap. I've sent it back for repair as it keeps dropping my array. Unless it comes back working, avoid that product. It does support upto 5 true hotswap devices, but only if you're lucky and get a working one.