I would think a logical place to enable or disable speed searches is on the panel menu. I generally want it turned off, because I don't want the search to start while I am entering the search criteria. It slows down entry of the search critera too much. I realize others might think differently.
I also don't think speed search should begin until you have entered at least a 2 or 3 letters. If you type a, Logos immediately starts searching for all the occurrences of the indefinite article ("a") and the keyboard response is really slow.
