I think the key to getting the best experience with IEMs is to go stereo. Panning each instrument will make the world of difference to recreate that 3D sound image we are all so use to when playing with wedge monitors, backline, acoustic drums etc.
With conventional mono set up, its just not the same and can sound like playing in a box. Everything being centre will eventually cause fatigue confusing the brain. And some ambient mics putting some of the room back into the mix.
Also, having control of your own mix. There are plenty of apps both for IOS and Android that can connect remotely to the sound desk.
It just takes time to get use to them and to use them in the right way.