Interface consideration - opinions requested

Hi; I hope this thread is appropriate in this forum part, if not feel free to move it.

 

I figured it was the best place to ask since it is about interface considerations regarding the application I am currently developping and I would like to get the forum members' opinions regarding these 2 options (see screenshots)

 

My document's view contains data arranged in a report control; there is a filter windows rebar, and a dockable preview window.

 

I wonder if, regarding general interface guidelines and end-user point of view, it would be best to :

 

1- include the dockable preview window within the document's view (1st screenshot)

 

 

2- include the dockable preview window in the Mainframe (2nd screenshot), preview will be displayed only for the item selected in the active view.

 

 

Personally, I think that option 2 is the best, because option 1 takes a full column in all the document's view and it could also be a bit disapointing as the end-user will be able to float several preview window if he has several opened document;

 

Thanks in advance for your opinions.

I think that it very depends on user needs. 

if sometimes he needs open 2 frames and using preview window compare content than option 1.

If he don't need it think option 2 is better