I think broadly it comes down to whether the brand is cool, recognisable not that it has a halo product.
Consider this list:
http://www.forbes.com/powerful-brands/list/
how many of them have a halo product? and i'm not just assuming halo is some 100k+ item as I understand that isn't the point.
Surely the point is more about what they brand conveys to you.
for me, for example, Audi means (in no particular order)
* German
* Well engineered
* reliable
and luckily for me I can afford a broad range of their products and as another poster says, the A4 platform suits my needs ,it really has nothing whatsoever to do with the R8 and as I can afford any A4 I want, I'll chose the "best" = RS, performance & trimmings.
In summary and imho "Halo product <> brand strength"
I think Halo products are just epeens and almost a thank you to the organisation itself. look at the GTR, disaster economically, i really dont think the average nissan owner even knows the GTR exists and is certianly not more likely to make me a buy a Micra

just my 2 pence
