There were several recent comments on this list about pgAdmin4 being slow which surprised me as I've found it to be faster than pgAdmin3. But then I saw pgAdmin4 on a Windows machine in standalone mode and realized what people are complaining about.
I'm running the python server script and then using pgAdmin4 in a web browser. I suggest that folks who are bothered by the speed (lack of) in standalone mode give the server + browser setup a try. The server is launched with a single command:
python /path/to/pgAdmin4.py
then navigate to:
localhost:5050