TortoiseHg has a very powerful datamine feature that searches the repo, and can be easily configured to look at a single revision,or the current working directory, etc. If you search for "loadFile" (say), it will list every line in which it occurs - giving filename and line number - I write Haskell code as LaTeX literate scripts and so there are no useful IDEs out there to do this for me, so having it in TortoiseHg is really useful..
The search feature in SourceTree seems to only search commit texts, and something (?) called "user".
Or is there a way to do power searching like this I am missing ?