Strike a balance.
Don’t go live too soon, but have enough real world usage to give you an indication as to what works and what doesn’t.
Listen to your application: if things fall into place you will hear a series of click-sounds. A loud click means a couple of things:
- the app needs less code
- the app does more
- the app is more usable
- the app looks better
- the app is easier to understand
When this happens (you’ll know because everyone will look up at the same time), everything has just fallen into place. Then, and then only, are you ready to go live.