I had a B&M like that, and a bar end Mirrycle that had come with the trike. Both were good, but the B&M was getting a bit old and tended to sag or fold in on fast descents, and the wormgear clamp had worn out teeth, so I replaced it with a matching Mirrycle.
mirrycle.com: mountain mirrycleThen, the first mirrycle snapped! Just clean snapped through the arm, on a rough bit of road at about 14 mph.
My other half fixed it for me - there was a cavity inside the horizontal arm (the ridged bit) that I assumed was intentional, but he felt about in it with some rod and found it was actually a bubble in the casting. He tidied it up, inserted a rod to splint it, and glued it back together. He also said that the ridging in the arm, which I assumed had some purpose, is probably why it's weaker. I haven't got round to refitting it yet, but suspect it's now better than new. Despite this, I like the mirrycle, it gives a very good view, and I don't have any trouble with my arms blocking the view, except when indicating, I have to remember to raise my arm a bit more than normal. And it only sticks out a fraction beyond the wheels, and it's easy to rotate the mirror bit in to fit through narrow gaps. I'll probably give both a sleeve of inner tube fixed at each end, so as to retain the bits in case of any further snapping. My other half did say that the sharp edged ridged design probably contributed to the weakness, and was a bit pointless.
I'll look at home later to see if I have pics of the various set ups.