What are the profit-sharing options with the second firm? As you've presented it, it sounds more like a contract position, with a base salary and guaranteed bonus, but no percentage of firm profits/out-of-state cases. The profit-sharing is where you can make serious money through other people's efforts.
Don't hyper-fixate on parental leave. That is a blip over a long career. Base salary is also almost entirely irrelevant if you're a partner, because you should get trued up at the end of the year based on your performance. If you are focused on those two things, you run the risk of ignoring the things that matter far more. You don't want to be in a position where you're jumping firms every couple of years and having to rebuild your practice, so look at the long-term financial and practice implications. Which firm will help you continue to develop your business? Do both firms have comparable associate and paralegal support, other partners who can mentor you, marketing support/$$, etc.? Over the longer-term, you will make far more money from developing a good book of business than you could possibly lose from a couple of months of parental leave.
The impression I get is that you're still thinking more like an employee than as an owner of the business. To be a successful partner, it can't be about guaranteed salaries and bonuses -- it has to be about the financial health of the firm, and how well each place will support you and allow/help you to grow your own practice, what kind of associates do they have so you can create your own little pyramid of people who work for you (and whose efforts you get paid for), etc. I mean, really -- if you're an equity partner, your "salary" is really a draw against the ultimate firm profits, so the difference is entirely immaterial in the end. (And if you're a non-equity partner, growth of your own business is even more critical, because that's how you get to equity partner). Which firm offers the best business opportunities -- and will compensate you best for success in those efforts? How does each firm determine partner compensation -- origination, billable hours, other people's hours, etc.? Again, those differences have a far greater effect on comp than whatever your base draw is.
Also, the firm may not be able to vary its parental leave terms -- if it's a firm policy, they need to apply it the same to everyone. You may have better luck negotiating in other areas.
IMO, being able to WFH is absolutely killer -- and I have a short commute. I suspect you may be undervaluing that, particularly with a baby on the way. But you also need to really think about how much work-life balance matters to you. You can't really argue for raises/bonuses/etc., at the same time you're arguing to lighten your workload. You need to figure out how much you really want to work, and then figure out how much each firm will pay you for that. How much insight do you have into each firm's financials? At my firm, the expectations for each class are clearly laid out in writing, and we see exactly what everyone else did and how much they got paid. So when I wanted to drop to 80%, then 60%, then 50%, I could easily tell how much it would cost me. There's no point in arguing for a raise, because then I'd have to work more to earn it; if my numbers stay the same, I'd just get more up-front and less at the end of the year.
At a bare minimum, get the baseline expectations for each offer laid out clearly -- you wouldn't want to be jump ship, only to be surprised at what they expect for that $100K bonus.
Finally, does either firm have a profit-sharing that allows some of your EOY $$ to go into your 401(k)? That's really valuable -- lets me put another c. $35K away pre-tax every year. I'm getting closer to actual retirement, and every time I think about stepping away, I think "but I'll lose my extra 401(k) money!" and bail. ;-)
