IB vs quant equity?

Guys, first post here (hi all). I'm turning to WSO because I'm at a cross road. I've spent ~3 years in IB but have since left for quant equity funds as a research analyst because of the crazy personalities and insane hours. I've been here for almost 2 years now and the work/life balance is terrific. I finish work at 6pm and there's very little stress... because we trade according to the model and we balance the portfolio about once a month. The pay is ok because we have a large AUM and there's performance fees but I'm getting a bit bored simply because it's so "unstressful" and the funds we manage are enhanced index funds (i.e., low tracking error/risk taking). There's already a quant hedge fund team at my firm so starting a hedge fund on our own is not possible/vested with internal politics.

So here is the problem, a former senior colleague of mine has moved to a MM IB who's building a new team and wants me to join him at the new place. He's offering the role of an associate, with pay a bit higher than my current and promised that hours won't be like a typical IB (he guided to ~7-8pm finish on most nights and only occasional weekends).

So here I am split between the two options. At the end of the day I'd want to be investing. My current role has (I feel) limited career progression opportunities but the lifestyle is good. If I stay in quant equity I would want to launch or become a portfolio manager of a hedge fund at some point. If I move back into banking, it's more exciting and there's a chance to build a business but it's also more hours and I'm not sure if it gets me closer to my goal of eventually managing money. If I spend the next 5 years doing deals then I will want to do growth private equity/special situations investing.

I was pretty good when I was an IB analyst and I'm also pretty good as a quant researcher (and I don't mean to sound arrogant) hence I can't really choose which one to do. If it was you which one would you choose?