Well, you shouldn't fix longer than necessary, particularly with prints, but that's another story.

The biggest difference is wash time. This can be really helpful with fiber papers. Standard rapid fixers are acidic. TF4 is alkaline. TF5 is ~neutral. Washing is much faster than with acidic rapid fixers.

Capacities and keeping properties are excellent too.

For films developed in staining developers, although it is still a debtable issue and depends on the developer, the conventional wisdom is to keep the process alkaline or neutral after development for maximum stain.