I too really have a problem with IEMs. I feel like there is a disconnect from both my bandmates and the audience.
I did a quick read of the thread and one of the key things I learned to do is to not only mix in the other guys, but to MIC THE ROOM and mix that in too. We do a stage right and left mic pointed out towards the audience. This give us some real representation of the room and decreases the isolation of IEMs when we use them.
I know a lot of the guys are stressing the importance of really nice IEMs, but mic-ing the room has made that part less important.
Ambient mics work for some.. and not for others. We tried them.. junked them after a couple of gigs.. we found they muddied the IEM mix when playing.
The disconnect that you feel DOES take time to adjust to... I have found that much of that depends on how you practice..
Like @RoadRanger above, I've ALWAYS practiced at home using phones, and even used to jam with the guys (in my back room) using only headphones.. so moving to IEM's was for me.. a non-issue.
There are going to be folks who can't/won't adjust to IEM's - for various reasons.. I know quite a few. I have one in my current band... has a nice system (G3 wireless, UE7 buds) but doesn't like the mix.. can't get his "mix" the way he likes it (amp in the room sound - which will never happen) and yanks out one, then both buds after a couple of songs.. I don't think he practices with phones.
For anyone having these challenges, I suggest one practicing at home using phones, and piping your songs into that mix to get used to that "sound" before you move to IEM's on stage.
@oldcatfish mentioned getting his head blown off with a volume spike. THAT SHOULD NEVER HAPPEN with a correctly configured IEM system.
If you are
wireless IEM, there WILL BE a compressor/limiter on your mix - usually built into the belt-pak receiver. Entry-level systems have fixed limiters, the upper-end models provide adjustable limiters on the receivers, along with EQ.
If you are
wired you NEED to make sure there's a LIMITER of some kind in-line. Churches with older Aviom (A-16) systems seem to forget that, and the standalone stations do NOT have limiters built in, so spikes ARE possible. I'm not sure if the newer models have limiters or not, but the Behringer P16M's DO have them.
Going IEM will save your hearing. Once that hearing is gone.. or damaged.. its NOT coming back..