The SM58 works okay for sax. But, the problem is that on a stand ... well, it sort of means that you have to stay pretty still
I'm not a shaker/mover/dancer (getting too old I guess), but I've noticed that even 1 to 2 foot moves back and forth make a huge difference. Hence, the advantage of the clipon.
Of course, one big advantage of the stand mic is that one can change the volume by moving back and forth
Honestly, the clipon sounds just fine. Until the wind comes up. I'll have to stop in at the music store next time I'm in the "big city" and see what they have in foam cones and see if I can adapt one to the AT.