Is Honors there selective? Is it as prestigious as an Ivy League school?
No, it’s not as prestigious as an Ivy, but prestige doesn’t correlate with quality of academics. UMich is a selective school that attracts very capable applicants, so honors is definitely selective as well.
Is it a matter of professors and opportunities?
Also, prestige is in the eye of the beholder. Better question is, what are you looking for in college and after?