I have been accepted into two STEM PhD programs and am currently trying to choose between the two. Both schools are good and I am confident that there will be no issues regarding funding. If any of you have any advice regarding what to focus on in my situation or more generally, I would be extremely grateful!

Program 1:

Supervisor/Lab
Young, motivated, well-connected, and successful PI starting a new lab.
Good personal chemistry, they seem kind, supportive, etc.

Topic
The lab’s and supervisor’s specialization is quite different from mine. Still, I have been assured I can work on my topics. I am pretty confident I can indeed work on them for at least ⅔ of the time.

Location
I would be working remotely most of the time. The supervisor has offered to arrange a permanent desk with another research group where I am. The supervisor also works remotely regularly.

Previous PhDs
Previous collaborators and students all seem to go on to have impressive publication records.


Program 2:

Supervisor/Lab
Main supervisor with an average academic record but the head of a large lab. Day-to-day supervisor with an uninspiring academic record. Both do not seem well-connected (e.g. no talks outside home country).
Personal chemistry was fine, they are kind and seem to give great freedom.

Topic
My topic has been accepted with next to no changes, so I can do exactly what I want. The supervisors’ experience is related, but not a full match.

Location
The location is a good fit for me

Previous PhDs
Most PhDs in the lab are industry-funded and don’t have terribly impressive academic records (I assume they have to cater to the companies as well). That said, two PhDs who just finished and whose work is reasonably close to mine did well.

It's hard to think 3 years ahead, but the best question fundamentally to ask is what position will they be in to help you into a career at the end of the PhD.

This partly depends on what you want to do - stay in academia, or move to industry. I'd think if it's the latter, Program 2 seems a bit of a no-brainer, but I'm thinking it's probably the former?

If it's academia, #1 seems better, but there are risks in a new supervisor with new lab. This can sometimes mean someone landed a big grant, but lightning does not necessarily strike twice. They may be about to launch a sparkling career; they may also not get any further grants and be living on borrowed time until the funding runs out. If funding runs out, then you may find the lab dissolved and you get shuffled into a faculty to finish the PhD, as Unis these days can be quite brutal with this. If #2 is well established, there might be a realistic prospect of a postdoc within the group, or at a connected institution, which is something to consider (the best way to check this, is to see/ask where their graduates ended up. Getting a PhD successfully is not as good a measure as whether they got a job afterwards).

The one thing I wouldn't factor so much is whether their interest/knowledge aligns particularly with what you want to study. In general you should expect a supervisor to provide general academic guidance on how to do a PhD, but not so much tell you what you should do (or know), as the theory is if things are working ok you should know more about that than the supervisor. A supervisor that does just tell you what to do by the numbers is potentially using you as a cheap lab assistant, which imo is best avoided, as you can end up running their experiments for them with little to show for it as they publish your data and give you little opportunity to learn.