Help a Brotha out :-D

[N1kon1k]

Hey guys
So since my last thread I have been saving a bit more than to just buy a lens.... I recently returned
a cokin Pseries Filter holder and I am going to upgrade to the Lee filter Holder since I'm shooting Full Frame.

My question is? Does anyone in here use or know anything about the Circular Polirizer that attaches in front of the filter holder? and if its any good?

My concern is if I'm shooting Landscape and if I Don't use all the filter Slots (creating space Between the lens and Polarizer) if I will Experience anything Funky...

I know they sell Square Polarizers to slide in the slot but I'm Not interested in those in case I need to twist the angle I wont be able to use a grad filter.

I'm Looking to buy: soft edge set .3, .6, .9
10 stopper
Polarizer