In addition to a feature suggested here
replace-functionality-t2669.html I think the search/replace dialog is missing two essential features.
1. The box is currently modal so when it's active, you can't move around the editor. This is handy if you want to be able to change the current selection and you are searching/replacing within that selection, or copy new code into the the dialog from the editor
2. I think the dialog should remember your last settings (e.g. I had it set to search within a selection on one search/replace, then went back in after another and it performed a global replace instead)
Also, I'm not sure if its necessary to have 2 tabs are necessary for search/replace - it may make more sense to just have just different buttons for Find and Replace. The comparison has been made before I know, but Dreamweaver's search/replace is very usable and I'm sure it wouldn't hurt to have similar functionality.
Chris