I would guess there'd be bigger wow factor in Australia for the Mustang than there would be for the Falcon in the US. As I've mentioned in one of my earlier posts, we Aussies never had much choice in 60's/70's 2 door muscle cars, so the US cars really do stand out on the road here as wow cars. Also, none of our coupes were designed purely to be pony car type coupes either - they were all derivatives of the sedan versions so all lacked the pony car trademark long hood and short deck which I reckon is part of the reason that Mustangs look so sporty against the local options.
Many people see the Falcon coupe in films like Mad Max and draw the comparison with the 71-73 Mustang, but really apart from the NASA style hood and the grille/bumper area the Falcon is a very different animal when you actually stand next to each of them and look them over (that's my opinion, because I've owned both). I've heard them described as a Torino-like derivative, and with all the obvious US influences showing in their design I would imagine that people in the States would be initially more quizzical about what it was rather than wow. Especially considering the hundreds of different types of awesome muscle/pony cars you guys over there have got to choose from on your own home soil, I would think that a Falcon would just kinda blend in amongst them....
Here are a couple of pics I found on the net that show the two cars together:
