I checked the scenario with SPRadGrid and SPRadListView web parts on one page and the designers looked consistent on my end. There was no interference between them, and the option for adding details table was only available for the SPRadGrid web part.
In the current version of the Sharepoint Acceleration Kit the web part designer has some limitations.
The default size of the designer window is 1200x800px but you can easily resize it by dragging its edges. You can check this in our SP demo site
The setting of the grid are not reflected back on the designer of the web part, that is why do not see the details table even if it configured on the grid. This is another feature which we have in mind for implementation in future versions of the kit.
Also the current version of the designer does not allow setting page size and dimensions of the grid so for now you will need to add those setting manually in the markup.
This is our first major release of this product line so lots of new features and improvements are coming on the way.
the Telerik team