The leakage test is primarily for electrolytic capacitors, which often get leaky with age.
The capacitance measurement isn't very accurate but will find open capacitors (rare!) and allow one to identify those without markings. The resistance scales are nearly useless. The comparison function on the EICO and others is also not too useful due to insufficient resolution, although that depends on the application.
Cheap service type instruments are not generally good for much. But their price indicates that. Once you use first rate gear you won't want to turn back. Having said that, there are places where they can serve useful functions but I believe it's out of proportion considering the extra fuss and bench space required.