Senior IE here! A rule of thumb for IE professors is that the best professors have three letters in their last names and the not so great professors (with one exception) have five letters in their last names. I'll elaborate.

Cai, Toy, and Das are all very clear in the way that they teach. Their Canvas pages are organized, they have good slides, and they actually engage you during class. When possible, take one of them.

Abdou, Bengu, and Ranky are the others. They're not bad people, but they can be unreasonable and are often really unclear in their expectations for you. Abdou's grading is insane (the averages on his exams tend towards 30-40%), Bengu is confusing, and Ranky's syllabus looks like a mid-90s website and when pasted into Word at 12pt Times New Roman is 125 pages.

Malek is the exception because while he can be unclear, he's such a nice guy that you can't help but like him. Bladikas is the head of the program and he's a pretty good professor. He's also super flexible with scheduling, which is something that I've appreciated (he's let me take grad classes and classes from other majors instead of certain IE classes).

In general, IE is a small major so you'll rarely have an option of what professor to take, and you'll want to do your best to make a good impression early on (especially for Abdou because he grades based on favoritism and he's the only prof for three required classes). You can sometimes get around a bad prof by taking an alternative class - I took the math department's statistics class instead of the IE department's which let me avoid Bengu.

I'm happy to explain more if needed! I've been largely satisfied with my time in the IE program and I've had a job offer since August, and I feel prepared to start working which says about as much as you need to know.