UM-Ann Arbor has more “resources” than UIUC (on a per student basis), which gives it more flexibility in managing it’s enrollment. Let me give an example.
School: Undergraduate Enrollment: # Tenured Track Teaching Faculty
UM-Ann Arbor: 6,162: 417
UIUC:9,337: 446
Purdue: 8,490: 361
Michigan has by far the lowest engineering student to Teaching Faculty ratio.
They also likely have more facilities(as compared to enrollment), funding for design teams, etc, than the other BIG 10 peers. UM spends substantially more per student than it’s peers. It helps having that huge endowment, and the large number of OOS students paying OOS rates.
This all translates into more flexibility in enrollment.
You can dig into the numbers, look at non-tenured track faculty, etc.
$ doesn’t = Best
UIUC is under a lot of financial pressure (due to state funding issues), but it’s clearly one of the best engineering programs in the country. But having more resources, does equate to greater academic support, more facilities, and in UM’s case, more flexibility in enrollment management.
Which takes us back to your original question. Which school offers the best academic support to Freshman. I would think it’s UM-Ann Arbor, it simply has the most resources. How much of a difference is hard to qualify, the same with how much of a difference it would make for a student.