Open-ended questions may result in a lot of feedback, but not much that's actually worthwhile. And often open-ended questions receive very little feedback. More info will help:
What's your budget?
For use with what other gear? Do you need other gear, also, or already have it?
Do you plan on open taping also, or strictly stealth?
For use primarily in large / medium / small venues?
What kind of music, generally?
Typically from what sorts of locations within the venue - up close, far away, in the coat room?