IMO, these two fish could not be more different, other than they are both hardy...
Asfur can get huge, even in captivity, at nearly a foot can be very aggressive at moments and are almost surely going to eat corals and anything fleshy. IMO, these are only good in reef tanks when small. I had one that was at least 2 inches thick and over a foot long and was really ready to head to the 10000g display in a restaurant in town. It was not mean, but it was not nice either... if that makes sense.
Chrysurus angels, on the other hand, stay relatively small at a solid 7-9 inches after many years and one can live in my 240g it's whole life, and has. I have also given them away to larger homes, so it is right there on the edge of that 240g range. I had one eat Z&P, but it left all else alone, including clams. I had two others that picked at nothing. They are among the least aggressive large angelfish, outside of Genicanthus, that I have ever owned, and are great tank mates.
I currently have a Chrysurus nearing the end of isolation ready to go into the display. I got it beginning of winter (ish) and it has gotten fat, non-skittish and is growing. It comes out when it sees me and eagerly awaits food. I love that they keep their stripes.
Chrysurus are collected from Africa and only available at certain times of the year. If you see one, be ready to purchase or you might not see them again for another year.