There is no doubt that a press with a tension meter, or other method of verifying the amount of stretch, will allow you to more consistently duplicate calls. However, that does not translate into sound consistency in a call. It is a commonly known fact with mouth call users that duplicating the sound characteristics of a call does not necessarily result from constructing another call exactly like it.
To those of us that make a lot of calls, it is apparent that very minute differences in call construction can make a significant difference in the sounds the call will produce. A press with meters will allow you to reduce the number of variables in call construction, however.
A hand jig is perfectly capable of producing great calls,....and for the guy that is only planning on making a few calls at a time, it is the more economical option, for sure.