Some pros and cons
I have dabbled in filters in the past and wound up asking myself the following questions, which led me to no longer use them (YMMV):
* What are the chances of one of these filters sending an important email to the wrong place? If it does get sent to the wrong place, what is the worst consequence? Am I willing to tolerate that risk?
In my case, the answer to these questions was that I could not run that risk. I receive emails from, say, an attorney that involve different clients. I could not trust the filter to always send the proper email to the right spot.
* To what degree am I using filters to try to avoid doing the work of thinking that only I can do?
In my case, the answer here was that I was hoping my system would automagically prioritize things for me, ultimately. I decided that, of anything, that was one area that I alone wanted to be responsible for.
* To what degree am I accepting more input than I can process?
In my case, there was an underlying scarcity issue at work; I felt that if I was not signed up for all of the special offers and email lists then I would somehow miss some great idea or option or sale.
After removing all of the filters and forcing myself to go through every single input in my life, I have moved towards a simpler existence which has become more streamlined and immeasurably more rewarding.
For example, I no longer receive promotional emails from stores. Have I missed any great sales? Maybe. On the other hand, I have spent far less money by not shopping BECAUSE of the sale. I do not miss the items I have not purchased. In addition, whenever I want to buy something, it is not difficult to beat just about any sales price with a small amount of Web research. I subsequently learned that, as far as saving money, it was far more important to decide WHAT to buy (and not buy) than it was HOW I bought (such as sales or coupons).
I was very happy the first weekend I spent where I received no emails, no phone calls, no text messages, and no mail. It was almost like a vacation. Of course, Monday morning they started again, but it was a nice reprieve.
If I receive so much input that I am unable to process it all according to GTD, then I scale back until I am comfortable again. The end result has been a much more focused career and a more rewarding personal life. I have less, but it works better.
Maybe this helps.
JV