Recent WesternU grad here. Also interviewed at several other schools, including DMU.
Rotations at Western are decent, depending on the track you get, but they try and make them equal.
Arrowhead is the large county hospital for San Bernardino county were WesternU and Touro-CA do a lot of their cores. You will learn a good amount here. Lot of pathology. A number of our students go to their FM/IM/Neurosurg/ObGyn DO residencies here.
The other big hospital we also rotate at is Riverside Regional Medical Center, the county hospital for Riverside. Also a lot of pathology here. Never rotated here myself, so I can only go by what I heard, but they teaching is pretty good. Not sure how many spots will be left for us here in the future, though, since UCR is opening up their (allopathic) medical school.
I also rotated at Downey Regional medical center and thought this was one of the best teaching sites. Good exposure, albeit a little smaller than ARMC. This was a bit of a far drive from Upland for me though.
After that, the rotation sites drop off a bit. Citrus Valley doesn't take that many students and is so-so. Long Beach is far unless you live at there, and is so-so.
A lot of students go to Chino Valley medical center, and it is decent for some rotations like IM/surg, and not so great for others (psych).
We also go to Pomona Valley Medical center for ER which gives good exposure, and you can do other electives here but when I was a student we only did ER for our cores here.
We do get 1 elective 3rd year which is huge. You can go anywhere.
4th year is all electives except for 1 month IM subI, 1 month surg sub I (can also be interventional rads, anesthesia), and 1 month ER. So 4th year is very flexible.
In general the education was what I expected, first 2 years are like any other med school, 3rd year rotations were average or some above average, and then 4th year rotations can be very good if you do electives at great teaching hospitals nearby at UCLA/UCIrvine/Kaiser etc. Wish, like all DO schools, we had our main teaching hospital like our allopathic counterparts so that we don't have to drive so much.