I have just put together a new media-server with a DH67CF (without the SATA faults) mainboard, and two Western Digital 3 terabyte harddrives, but there's trouble ahead :-)
If I run the disks as AHCI, they are detected correctly as 3 tb. Once I enable RAID and go into the raid configuration utility (CTRL+I) they show up as 746 gb only. It makes no difference to enable UEFI or not. It also makes no difference if they are run on the blue og red connectors.
The funny thing though, is if I install Windows on a seperate SSD and leave the two 3tb "alone", they show up in Intel Rapid Storage Utility as being 3 terabyte (probably becuase no RAID arrays are configured, and it falls back to AHCI, which works).