Priority queue on Cisco 3702

I am doing some AP testing on our Ixia VeriWave and came across some unexpected results I'm hoping someone on here might have more info on. I'm still waiting to hear back from Cisco on it.

I am performing testing on the various maximum throughput rates of a 1x1:1 connection using different QoS markings. From wired to wireless my EF marked traffic has very little capacity. At 64 byte frame sizing I can do 3mbps sustains. At 1518 bytes i get 18mbps. Any other DSCP value does not yield this same results (eg: AF41 gives me 177mbps @ 1518 bytes)

I know its hitting the AV_VO queue but if I mark a packet from the wireless to wired direction using UP 6 or 7 I cant replicate this response, it seems to be specific to EF marked traffic. Does the 3702 have a undocumented priority queue?

Edit: all of this testing is done on 5ghz inside of a RF testing chamber, no interference possible.