There is more to how a hosptial receives and treats trauma than just their trauma level. How many trauma centers are in the area, how much trauma is in the area, what the trauma environment is (highways, rural, urban, costal, et cetera), and relationships with EMS can all play a bigger role than what the trauma level is.
Keep in mind that all trauma centers must have ATLS trained physicians and trauma trained nurses. How hospitals conform to this can vary, I have seen level 1 and 2 trauma centers who only have TNCC as a requirement for nurses that work the trauma pod which is a small minority of the ED staff. Virtually all of the difference in trauma levels is what happens after the ED, if you are in a "low" level trauma center but the facility is alone in a rural setting they may see more trauma than most urban hospitals, but they will just have to transfer after the patient has been stabilized.
I would also be cautious of hospitals that purport high numbers of trauma cases, these are often inflated with transfers or cases that are of relativity low acuity. Very large hospitals may have EDs with one hundred or more rooms, so even if they get a fair number of traumas you also should consider how often you will actually be participating in trauma care.
I have worked at Level I, II, and IV centers (the latter of which being more of a formality so that we could keep our trial/specialty patients if they were involved in trauma). The most trauma I ever saw was at the level II, but that was because there were relatively few trauma hospitals, EMS loved us, we were the closest facility to almost all of the regional highway, had a good reputation with the community (compared to the county hospital), and most importantly I could work in the trauma pod as much as I wanted (a lot of the nurses who worked there hated trauma). When I was at the level I there were 2 field traumas that I received after working there for over 2 years.
Long rant short... make sure your tour the department and actually talk to the staff nurses before you work somewhere. Reputation and trauma level don't necessarily mean a whole lot when it comes to the actual patients you receive.