Tiffen Dfx Digital filter plugin

I am trying the 15 day evaluation for the Tiffen Dfx filter plugin, 
http://www.tiffen.com
and it seems to provide enough reasonable quick 
fix solutions to do away with glass filters such as ND & color GRADS, 
Polarizers, and many others.

I was curious if others here have tried or use Dfx, and any opinions as 
to value given the cost $299.99 for the Complete Edition, and $159.99 
for the Select Edition. If this is a viable means of doing away with 
physical filters, it could amount to an enormous saving.

Regards,

Savageduck