Well now that the votes are in, let's see what it all means.
It is not surprising at all that the response time for the TCP protocol is much lower for the wired network. This can be attributed to the simplicity of the connection - no DSSS modulation, no WEP, no IEEE 802.11, no interference, etcetera. Also, there also seems to be no significant response penalties for encrypting the data packets.
The results for the TCP throughput fall short of my expectations. The company claims the cards can achieve 3.8-4.0Mbps sustained, but these figures show that the cards perform a bit lower than that with no encryption penalties.
Once again, the wired network beats the wireless by a large margin. And again, the encryption of the data has no effect on the throughput.
These figures are quite surprising, especially since there was only a 2-meter separation between the two cards without any obstructions of any kind between them.