It shows 15 items by default, which seems more than enough for me, and also offers search/filtering. But if for some reason that's not enough, then I guess it does miss out on that one item. I can't possibly imagine why you would need to see more results on the screen at one time, but everyone has different needs I suppose!

Maybe I wasn't clear. I was talking about the preview panel. Sometimes I copy content of a source code (*.cpp) file, and I need to quickly look at what I have copied in the preview panel. I have to scroll a lot to look at the source code. In ClipBook I just resize the clipboard history window to see more in the preview panel without scrolling.

Alfred just doesn't meet my requirements. The filters don't work for my needs.