Options->Debugger->Locals&Expressions

There is a checkbox "use debugging helpers"

If I check it, debugging and stepping through the code is pretty much unusable. It takes up to a minute to step into a single functions.

As soon as I uncheck this box, debugging is vivid fast. Of course I don't have the convenient data view for complex classes.

In understand that there are python scripts running through the available data for proper formatting. But, does this explain this slowness?