Was wondering how often you clean the lens front Element, I personaly dont clean very often at all , Unless there is an obvious big smudge, If I do it's a quick blow to remove dust, Then Huff on the lens and in a Circular motion use Cotton/Micro Fiber to remove the smudge , Thought this Artical I found interesting , Wondering what your thoughts are on this Subject, Here's the Link to an Interesting read !!
http://kurtmunger.com/dirty_lens_articleid35.html
You'll get a shock at the end PS : I dont use UV Filters and I wash my NDG Filters in luke warm running water and soap , Thought Id just add the extra stuff - Bill