Cokin holder + Lee filters

I'm interested in either a Cokin or Lee filter kit, after doing some research it looks like Cokin has the better holder (less liable to fall off) but Lee has the better filters.  Is anyone using such a kit (Cokin holder + Lee filters), and what is your experience?  I imagine that both using 4x6 filters there wouldn't be an issue but I'd rather be sure before making the plunge.

Thanks!

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"In technology I'm placing all my trust"
http://www.AdamMoozPhotography.ca