I have also used the Skip Dr (the motorized version which is much easier on your arms) and I have to say it is decent but not magic. There are some discs I could not save at all, especially those with deep radial scratching, but in the majority of cases it did fix the problem.

Stay away from the solutions that you just have to rub on, they don't ever work as far as I can tell, buffing the disc is the only way.

And it has been my experience that there is a huge difference between how well different cd drives rip cds. Some drives can read scratched discs much better than others. It pays to try to rip bad discs like this on every cd drive you can find.