Approval voting absolutely sucks. Not for any mathematical reason, it may very well give us the best results mathematically, but for psychological reasons. If you give approval to both the safe (popular) candidate and your preferred one, then you won't feel you have expressed your preference once the popular candidate wins. If you only approve your preferred candidate and an opposing (very undesirable) candidate wins, you again regret not voting tactically. In either case, you justifiably have no confidence in the results.

Also, as a candidate, how do you get people to not mark other candidates in addition to you? The answer is you don't run on your own positions but attacking opponents. Not very healthy for democracy.

I need to think more on STAR.