I ran across the Column chooser feature for the NCrunch test window and it was easy enough to figure out how to add columns but it was definitely much trickier to remove columns. I eventually found that dragging the column to the lower portion of the test list changes the cursor to the X and releasing the column header there removes the column. I was playing around a little and found it was somewhat odd how the cursor reacted. In particular dragging the column header into the code window onto code results in a cursor similar to when you're moving the tests. Moving the column header into white space in the source window changes it to the remove column cursor. (And actually it's not all white space it seems to not be consistent.)

Suggestions:
1) Right click context menu on column header should give an option to remove the column from the view.
2) Treat all of the code window as if it's removing the column (and maybe treat all other contexts, class view window, property window the same way). I could see also changing it back to the normal cursor in all areas, mostly I'm just voting for consistency regardless of where I am in the menu because a different cursor makes me feel like it should react differently.
3) Change Column chooser window from showing only unused columns to show all columns and differentiate them somehow. Unchecked check box, faded, or something.
4) Interestingly while writing this up I found that you can have the columns sorted by a non visible column and it actually puts the caret in the customization window on the tab. However you can't change the sort using the columns unless they're enabled. Figured I'd mention this because it seems like possibly overlooked behavior.
5) Possibly set the search text entry box to stretch to the remaining window length. Seems like wasted space to not let that text box grow since there's no other controls after the search box.
6) Not sure the best way to resolve this, but it's easy to lose the customization window behind the other windows. There's no indication it's open and you can't ctrl-tab or alt-tab to it. So maybe keep that window on top, treat it as a normal VS dockable window, or maybe just add to ctrl-tab or show the window in alt-tab/taskbar?

Obviously all low priority and none of them prevent it from being effective, but if you find yourself bored and wanting to feel productive doing easy UI work this might be a list to look at.

Thanks,
Mark Smith