Originally Posted by deluxx 
Thecus recommended that I try out their beta firmware v2.01.10.6. At the time I had only two good drives so with their beta firmware I created a raid 0 which completed fine. I did not any full stress test just a few file copies (250 MB) and it works fine. I just received 2 replacements drives and will create a raid 5 with my 4 drives in the next couple days. I also RMA'd another drive which I should get a replacement back in a couple weeks. I will post my results regarding the raid 5 with the beta firmware.
Here is an update. The beta firmware v2.01.10.6 seems to fix the issues where it would hang on creating/building a raid. The raid 5 building completed fine and has been stable since last friday. I also have TLER enabled on the drives, read and write set to the default 7 seconds. I don't plan to test it with TLER disabled and don't want to take a chance of having the raid creating breaking the drives.
I did a few 100 GB file reads and writes to make sure it is ok. Don't have the time to do any more.
So to summarize -
Beta Firmware v2.01.10.6 works with Western Digital 2 TB (WD20EADS) Drives
Raid 5 (4 used drives + 1 spare)
Usable Disk Space - 5407.1 GB
Raid 5 Total Disk Space (4 drives) - 5583.4 GB
Single Drive Raw Disk Space - 1907.7 GB
5 Drives Raw Disk Space - 9538.6 GB