I used SpinRite etensively in my Windows days and was both very
impressed and very satisfied with it. I didn't know it had now been
made to work with Linux but, from my experiences with Gibson Research, I
would have no hesitation in saying that, if they say it'll work with
Linux formatted drives, then it will, without problem.

SpinRite does not run from within the OS - in order to do the kind of
in-depth analysis and recovery that it's capable of, it needs totally
free and unfettered access to the HDD. For this reason, you need to
shut down your OS and boot from a floppy to run SpinRite. It can take a
lot of time, especially the first time you use it - the first time I ran
it on a 4GB drive, it took nearly 12 hours on a 750MHz Celeron - but it
is a truly impressive tool and I thoroughly and heartily recommend it to
everyone. Usual disclaimer - I have no connection to the company or any
of its employees; I am just a very, very satisfied user.