Update: I had both my third and fourth interview. I didn't think my third went very well, but apparently my interpretation was inaccurate as he recommended the company hire me. I felt like I knocked the fourth interview with senior management out of the park, but its always difficult to tell if your assessment of an interview matches theirs. But I guess it did, as they made me an offer.
I told them I needed some time to think it over, and if I did accept there would be an open ended question regarding my start time. Technically my firm could "force" me to finish a 90 day time period, but they'd have to pay for the time. I doubt they would, and would elect to take the pay savings by waiving the requirement, in which case I'd need a short transition period to move my cases over, maybe two or three weeks. But we can cross that bridge when we get there.
Every meeting I have with the new company makes me more comfortable and optimistic regarding the position and the company's future. There are no guarantees at anything, but its positive.
To help me decide, I called up a few people that I strongly respect their opinions on. One was a former partner of the current firm, who is still somewhat involved. We talked for a long time and, based on a few things that I don't feel comfortable sharing online, he felt the current firm is quickly heading to an unsustainable level which would force me to seek some sort of an exit strategy in the coming years. The way he viewed it, since you often know very little about a new job, taking the new job would be like jumping off a cliff and hoping your parachute opens. But if my current position will likely require an exit in the coming years anyway, I'll have to jump off that cliff eventually, only if I wait I may have a backpack instead of a parachute. If I jump now, I may free fall, but if the parachute opens I'll be years ahead of where I'd be if I waited to see what happened. The analogy really stuck with me.
Profound advice given to me by many, and I greatly appreciate all the contributions on here. This one, in particular, for reasons I can't identify, stuck out to me the most:
My advice is simple - take the in-house job. I've never met an attorney that regretted going in-house. Ever.
Ultimately, I think I'll take the new job, and make the leap.
In the meantime I enter a round of negotiations with the new potential employer. I requested more information on the health benefits, and I know I'll counter with a request for more vacation time. They actually offered more in salary than I requested, so I'm leaving that be.
If I make the transition it will likely involve tax consequences for me. Because I'm currently in a partnership, I'm set to have a tax draw in April. If I leave before April I'm not entitled to the tax draw, but I already took the salary. So I'll end up owing the fed and the state several thousand dollars. I'm going to see if they'll be willing to provide a signing bonus to cover the taxes, but we'll see on that end.
In the meantime it makes things very awkward. I know I'm most likely going to leave, but I don't have an offer to accept just yet. My current firm takes a "scorched earth" policy if someone quits, so I can't discuss the possibility of leaving, or tell them I'm negotiating an offer, until I'm ready to accept. If the negotiations break down and I told my firm I was planning on exiting, I'll highly anticipate I'll be either forced out at the worst, or cut off work wise at best. Which is kinda a sad and depressing way to show up to work every day.
Thanks again for all the advice, and I'll probably post the results once I actually make a transition.