I did not phrase it correctly: loading speed is not slow
The fact that everything loads in one page makes it slow.
This is only a problem when you have large numbers of custom types.. which I have. So on my shared hosting it takes typically 30-60 seconds to load the whole interface, while my page still has decent loading times.
Dear Mertnuhoglu! This fixed it temporarily for my custom type too. @daniel, we will be eagerly waiting for the update — sorry for cross posting about this issue on Github.. as I just noticed this answer!
