Well, I haven't had to clean my filter in over 5 years, but I still pre-rinse (yes, I know you're not supposed to need to anymore, but I don't want to risk it), so I check the filter regularly, but it's clean.
Ha! That's not quite how my model works (you just use a wash pack to clean the whole machine) but yeah, when I did finally clean the filter because a plastic straw was stuck in it it was not so bad considering.