If the disk is not working well though, what you want is to be able to copy the contents as quickly as possible.
I'm not sure that these recovery programmes are a good idea if the disk is in poor condition:
would creating a sector by sector image of the whole drive be a good idea first ?
Then you can mess around all you like with different recovery programmes, if the HD dies, you have a copy.
Disclaimer: I have not made a sector by sector image of a drive. I think it should have everything on it though (see if other people confirm that).