I have used this shape ever since I started playing the guitar in the 80s. The original reason was that it has three corners, i.e. lasts three times longer, and as I was a poor schoolboy, even small things like this counted. As I got used to this shape, I still use it.
These picks are much smaller than what picks with these shape are, so I give a 4* for handling, other than that they are OK.
My bigger ctirtique goes to the fact, that there is no 1.0mm, just 0.7 and 1.2. The former is too thin the latter is too thick for me.