I have not, since I don't want it to proxy arp. But I wouldn't think it's a matter of responding to ARPs - it's a layer 3 device and routing is working happily, so things upstream are routing the packets to the outside IP of the LTM, and the LTM is picking up the packets.
If I ping the address from the LTM itself, it responds. If I ping the address from a host on that network, I see a reply. But if I ping the interface from a remote box upstream, I see the packets hitting the LTM's outside interface when I do a (non-promiscuous) tcpdump, but I never see a reply on any interface.
Nimbostratus