Hi Chony,
Free advice is worth what you pay for it.
In that regard I say save your money. Getting usable information dealing with human ears is like trying to catch a shadow. There are to many variables, hall size, your equipment, tolerance of your audience, etc.
Having a trusted listener move around the room to give you a thumbs up or down has worked for me, and it's a lot cheaper than a meter.
If it's really a problem and money is no object go for the Bose PAS, bingo problem is minimized.
Have a great holiday!
rp