I don't use one. I like not paying directly for content and accept that ads and tracking are the price I "pay". I personally don't feel comfortable taking something without holding up my end of the bargain. It's really not a big deal. Sometimes I see products I want to buy or things I looked at and forgot about and end up buying them. It's also not the horrific and torturous experience I read about on here. I wonder…
If you're paying nothing or just a little, and/or it's very fast then the extra time/cost of the ad content is negligible.
On the other hand, if your internet connection is slow, expensive or you have a small monthly quota, then any time or cost involved in downloading largish volumes of ad content becomes a huge fraction of your costs.
I once had a monthly quota of two gigabytes when travelling. An average of only 60 megabytes per day. It doesn't take many two-three megabyte webpages full of ads to soak up that 60MB daily quota.