I personally would do ICU vs. ED. I do SICU myself (my hospital's TICU and NeuroICU is the SICU; we get a relatively small number of general surgery/CVTS pts) and full disclosure have never worked ED. Our ED nurses are assigned to the stabilization area, vs. the ICU nurse, but I don't know what the role of the RN vs. the resident looks like.
But based on what a nuthouse our ED waiting room looks like, compared with the number of trauma pts who are admitted to the SICU, the trauma nursing seems to be a very small portion of the ED. Now we're an inner city level 1 TC, and my state borders several states that MAY have a level 2 TC or two, so we see a lot of severely, SEVERELY injured people. We get your typical MVCs, GSWs, stab wounds etc. but also some horrific farming accidents by nature of my geographical location.
But for every shock trauma pt that comes in, there are dozens of others that present to the ED with N/V/D, headaches, sore throats...even a family with head lice. Yes, head lice. At 0100.
I'm sure it is awesome to care for those shock traumas as they emerge from the helicopter, but as an ICU nurse, trauma care is a much larger percentage of what I do. And really, they frequently leave the stabilization area NOT stabilized.
They might roll up during a brief window of opportunity, and then we do the massive transfusion, start the drips, etc. to buy them some time to get to the OR. And then we get to combine Nursing 101 with the high-tech and really make these people better.