I had the same thoughts as you before I started the application process some months ago. I never thought I would have ranked the two pgy2-4 programs I interviewed at at the top of my rank list (#1 and #2), but I was really impressed with the training at both programs and thought the prelim/transitional year would be worth it as long as I didn't go somewhere that would be basically like 4rth year with a salary. I am hoping the prelim year (I will be doing prelim medicine but with a month of ER and 3-4 additional electives in any dept so im hoping to do more than just medicine during the year) will help me learn to be a good all around doc so I will have that down somewhat before I begin trying to be a good emergency physician. I know EM is different from IM, but i'm convinced there is a lot of general medicine in EM and knowledge from an intern year in IM wouldn't be completely useless and might actually make me more competent (I wonder what im gonna think a year from now though LOL). I'm hoping I will be a better physician at the end of 4 years of training as opposed to 3, but I by no means think that 3 years is not enough it was just my personal preference. I would have preferred a 1-4 but felt a little better after I looked at all the different rotation blocks of the programs I was applying to and noticed that the pgy2-4 programs were just about all EM or EM related (eg. tox, US, trauma, peds em) with the exception of 2 weeks of ob, anesthesia and 2 months of ICU as soon as you start the pgy-2 year so it was almost equal or equal to the # of EM months in 1-4 programs and more than the 1-3 programs.