I remember a guy at work had a Muddy Fox MTB in the late 80's Cool as.
Now I see Muddy Fox only in an Argos catalogue and think that although I'm no bike snob, I wouldn't buy or recommend one for that simple reason.
If you're asking about our opinion in order to test marketing strategies, then my reply would be to get them out of the catalogues, and make sure you can source and deliver competitive componentry or else "proper" cyclists will asociate them with Dunlop and British Eagle.