I'm finding myself trying to shoot more and more long exposure shots during the day under bright sunlight.
I concluded that it would be handy to have some ND filters.
Now I have two (affordable) brands in mind:
Hoya and Tiffen.

I read the tutorial of McQ about filters,
is it possible that Hoya is not using the ND8, ND16 connotation anymore?
because on BHPhoto, they are all described using 0.3, 0.6, .. factors.
(http://www.bhphotovideo.com/bnh/cont...t=Submit+Query)

Now, I'm wondering,
what great advantage would I get buying a Hoya 0.9 instead of a Tiffen 0.9.
They're both Glass.
Also, the coating factor comes in again... is it worth buying a 'multicoated'?
Finally, how do I distinguish a 'REAL' ND filter from a 'grey' ND filter that I heard about..?

Thanks!