Since the Cloud is always Wired, it can’t be a firmware issue causing slow wireless performance.
As far as wired performance goes, it’s definitely not a firmware issue (at least not a systemic one.) I can read/write at 5x that rate to My Cloud. For short bursts, I get 110-120 MB/second.
If you’re only getting 12MBps wired, I would make sure everything in the path is actually Gigabit Ethernet – 12 MBps is the max for only 100 meg ethernet.
Here’s some more detailed things you can look into:
http://community.wd.com/t5/WD-My-Cloud/HOW-TO-Troubleshoot-NAS-Performance-concerns/m-p/618695#M1256
