Is the Picosure laser or the Astanza Trinity laser better for black tattoo removal?

Realistically lets talk. The trinity would be best. The recent advent of pico technology has started a wave of inaccurate information from the system removes tattoos in half the time to it can remove any color. Simply not true , both statements. In fact the current recommendations for tattoo removal are using the Q switched system for the first 4-6 sessions then switching to pico if you desire. 

The gold standard Q switches tend to remove the average tattoo in 8-14 sessions, I find most are resolved around 11. Picosure is currently in a class action suit started by physicians who paid the high price and have little success with tattoo removal . In your situation if you have someone with the astanza that would be a more effective laser that the other one. 

In my office I have multiple tattoo lasers like the picture 755 wavelength and the medlite 1064 wavelength.  I find that different pigments respond differently to different lasers and often use both lasers to treat many tattoos at the same session to get optimal clearing of tattoos.  Black tends to respond well to most lasers and is easier than many other colors.  Good luck!