system
Given the following post, respond as if you're commenting on Reddit:
human
Professors of AskAcademia who supervise grad students - do any of you lack expertise in your student's chosen research area?

I'm currently trying to decide between two CS programs for my grad studies. I was admitted to my top choice (Masters with Thesis) and will be working on machine learning in the context of autonomous vehicles - this is a research area in an interdisciplinary project that definitely has me excited. However, a former student has told me that while the lab and program is great and that I won't regret it, the prof has almost no expertise in machine learning. The school however is a top 10 for CS in North America.

The second program offers a PhD and is from a school that's not really known for its Computer Science program. However, the prof and his lab seem like amazing people to work with and I've been offered a very generous stipend. The prof also has published papers in the research area I'll be working on. However, while I do like the area of work I don't find it as exciting as the one offered by my top choice school above.

I'm mostly comfortable working independently and enjoy flexibility but I also like to have some guidance from time to time, especially when I get stuck. For this reason, I'm having a problem deciding between the first option and second and would really appreciate your perspectives on this situation. Thanks. :)
gpt
You'll get a variety of opinions on this, but mine is that you should evaluate a PI on a managerial rather than an intellectual basis.

Most of the questions you'll need answered are contained somewhere in the literature if they can be answered at all.  No professor - no matter how brilliant - can ever hope to know more than a small fraction of what is contained there.  So the individual brilliance of your professor can easily be replaced.

What can't be replaced is your professor's ability to maintain a functional lab, help you through the hurdles of your career and secure stable funding.

For me, the easiest way to judge this is to take a look at your prospective peer group - the grad students you'll be working alongside.  If they interface well together, are generally happy in their work and seem to be advancing well in their careers, you want to work for those professor - even if they're not the leading expert in your field.  In contrast, if those grad students are working every other semester at Starbucks to pay their rent, hate each other and regretting their choice to attend grad school, you probably want to avoid that professor.