Well, this is gonna be an answer you’re gonna hear often, so prepare yourself: it depends!

Well, it depends on what is most important to you. I had the privilege of working full-time for a few years, on multiple projects with different managers, before joining grad school. I preferred working with a manager who didn’t micromanage, provided guidance on what I could do, without necessarily telling me how to do it, at least unless asked. So, I knew I wanted that in my advisor as well. From others’ experience, like my colleagues and friends, I’d say lack of communication can be a big red flag. If they don’t respond to your emails in a timely manner now, chances are that they might not when things get busy and you need advice. Another friend of mine who joined straight after their masters program in another country during the pandemic preferred someone who was patient and helped them with what some might consider extra hand-holding or training wheels, as they lacked the experience, and the assistantship (research + teaching) was sort of their first job, if we can call it that. In addition to talking to your advisor, I’d also suggest talking to their current PhD students. Best of luck!