To be honest, I didn't have much luck with ghost shrimp. My tanks tend to run a little too hot for them, so they never lived more than a few months. Ghost shrimp also tend to be one of a number of species, so it can be hard to know what their requirements are.
On the other hand, I have had amanos for around 18 months with only a couple of losses (due to accidents or stupidity on my part). My cherry shrimp also breed like crazy, with very few losses over the last year or so.
Other shrimp that I haven't kept yet can be harder to keep, such as crystal red shrimp or bee shrimp. I know if I ever want crystal red shrimp I would have to get a chiller, as they don't do well at higher temps.
So, in my experience, I wouldn't say ghosts are not a good indicator of shrimp keeping skills.