K-7/K-x Digital filters

Hi guys!

I'm very intrigued by the digital filters set of my k-x and I was wondering how do they fare in performance comparing to optical filters or even other software.

Here's a slow night photo combined with the star burst digital filter,
I think it adds a nice mood to the scene

does anyone have some experience using these (positive or negative)?
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http://www.snapgalaxy.com/Pablom