It works for me anyway. When connecting two openwrt containers via a switch in GNS3 I get 1.15 Gbits/sec. When connecting the wan port on one container to the lan on the other I get 3.18 Gbits/sec. I also tried OpenvSwitch but only got 158 Mbits/sec.
BTW the Cloud device seems very slow, but the NAT device is usable if you need Internet access (package download).
Okay, I will try again!!! 
Maybe I did something wrong. 