daqscope: odd practices? Is this a good program?

In the DAQ demo program daqscope, the main figure ('hFig') contains a UserData property in which is stored the main data structure of the program ('data'). 'data' itself has a property which is the handle of the main figure (i.e. 'hFig'). This seems oddly recursive. Is this good practice? Is this in general a well-written program, containing recommended methods for using the daq toolbox and gui interfaces?