But if it's a residency program, then you'll work w/ a different attending or senior resident each shift, and they'll be busy supervising other students, interns and residents as well. You're not gonna get much face time w/ them and they may or may not care to ask you what year you are and what you're interested in.
Not sure where you rotated, but either the attendings/residents are not personable or they just are overworked. I have almost always (>90%) had time to talk with the attending/resident I was working with, even if we were getting slammed. Heck, yesterday I saw 10 patients in 9 hours as an MS4 and still had time to chat. And, almost always you will be reporting directly to an attending or a chief resident (both of whom write evals at my school) as a medical student.
And you're gonna want to get a SLOR b/c if you don't, you'll get asked about it during residency interviews and it'll look bad. And you'll have lost your chance to get a slor or do a real rotation at that program b/c they're not gonna let you rotate twice.
I'm pretty sure the OP is talking about doing a 3rd yr rotation at his home institution and then he would still do another 4th yr rotation to get a SLOR. No reason to get 2 SLORs from the same program, just doesn't make sense, nor should it raise red flags in the application process.
Plus, by taking EM early on you're wasting a great educational opportunity since you won't know wtf is going on half the time.
Hell, 1/2 the time I was on my ENT and CT surg (don't ask, had to rotate through both...) rotations I didn't know what was going on, how is that any different? But, it sure let me know based on personalities and what I witnessed, that I did NOT want to enter those fields. And, talking to most MS3's that have taken a rotation in EM at my med school, almost all have agreed that they thoroughly enjoyed their rotation, learned a lot, and were never just cast aside.
@mtwop - If you are going to shadow more, I would look to shadow during the day as well as overnight. Not only on overnights will you get more trauma (usually), but you will really see the ED at work. Also, around 3-4am, it usually slows down and you can have a bit more chatting time with attendings/residents.