"He's not someone I want to sit next to for too long, but we're going to start a business together and spend lots of time cooperating on massive live changing decisions."
That's a hard no.
That's a hard no.
It's possible I might learn to tolerate this potential cofounder as well, if I spend more time with him.
It's certainly not my first choice but he and I have nearly identical interests in terms of the startup we want to build, as well as perfectly complementing skillsets.
Some people are okay with that. Some aren't. Are you?
And what good are experiences and interests if your visions aren't in line with each other, or you end up just never liking the guy? I mean, if you can find things to like and get along- that's great! But the fact that you're asking this question to begin with is troubling in itself. You shouldn't have to ask, IMHO. You should just know. And, I suspect you already do.
I was planning on setting up like a 3-month part-time working relationship where we can work together on some side project to get to know each other better.
A 3-month work commitment is not much, plus if I go into it and 1-month later I decide things dont work out, I can just leave.
But I'm wondering if it's worth investing time for this 3-month work arrangement at all
Have you discussed this with him? And if not, why not? You'll be tackling much bigger issues together in the future, so tackle this one. What does he think? It might be as simple as saying "You know, we have a lot in common and I think we could work together, but our personalities just don't seem to click. I'm concerned about working together long term. What do you think?"