I spoke with the recruiter, had a technical phone screen and then went to their office for a three hour series of interviews.
The people I met on my interview were all friendly and seemed to genuinely enjoy working at the company. The issue I ran into was one of apparent contrary expectations -- I ran into this on two important fronts:
(a) The hiring manager stressed that the job involved coordination, process transformation and technical leadership while the CTO seemed to think it was hands-on technical work and seemed off-put when I floated the same basic ideas for process improvement that others had seemed enthusiastic about.
(b) I have a six month-old who needs to be picked up at 6 PM -- my wife can pick her up once or twice a week, but I need to be able to be there (besides, if I'm not seeing her for a few minutes a night on a regular basis, what's the point?). The managers I spoke with maintained that this wouldn't be a problem, but the other folks I asked about this told a different story; most of the office comes in late and stays late, and The feeling I got from them was that having to leave around 5 on most nights would be a problem.
While (a) is something I could have worked with as I established myself in the role, (b) is a dealbreaker. I mentioned this specifically in my phone interview, so I was disappointed that I had to take a day off to find that this would be an issue after all. You can argue that the opinion of the managers is the one that matters, but in a role where you're expected to move the organization by exerting influence (rather than having direct reports) that really isn't the case.
In the end, we arrived at a situation of mutual disinterest. Their HR representative did call me to let me know that they'd decided to move in a different direction, however, and I feel that reflects well on the company.