The spring mechanism is great so it can hold itself on the cab pretty nice, but setting up the angle of the mic gets a bit tricky cuz of the design, you can't get a good tight setup without using some sort of clamp to help. I used it at a live gig once and mounted it on the side of the cab, and halfway through the show, the arm decided to just let loose and dropped the mic position to where it wasnt facing the speaker at all.
If possible i'd recommend to mount it on top of a cab to reduce that risk, but other than that, just stick to a regular mic stand.