I bought a pair of Bayersan brass ones recently. Aside from the large barb on the back of them which made it difficult to fit the 6mm brush hose to them that I use on all my brushes, the spray pattern was completely different on one compared to the other. One was nice and wide and the other was really narrow. I have to say though, that though I like fans for easy regular maintemence cleans when not a lot of water is needed, in my experience they don't rinse as well as pencils when a more thorough rinse is called for.
I did a couple of PVC cladded porches recently that were quite dirty and after scrubbing there was a lot of loose dirt that needed rinsing off and the fans just didn't cut it even on ful flow compared to 2mm pencils at two thirds the flow rate. There was just no contest. The pencils won hands down. It was much easier to see on white PVC