The interviews themselves were very positive experiences; my negative rating is due to the post-interview follow-up:
Shortly after submitting my resume, I was invited in for an interview. It was very casual, basically me and the interviewer chatting for an hour. The conversation was pretty much dominated by him explaining his vision for the company and its expansion, so I was somewhat limited as to what I was able to convey about myself, but as a whole it went okay. I was told they'd be narrowing the field and inviting people back in for second-round interviews later that week. I figured it was 50-50 that I'd get invited back.
Lo and behold, I was. An interview was set up for the same day the following week, where I met with two different people over the space of an hour. I was getting very positive reactions from both of them, and I felt the interview went very well. The interviewer who had invited me in said that she'd contact me later that week about "next steps". I was fairly certain I would receive a job offer.
The week ended without me hearing anything from them. The following Monday I sent them an email to check in and ask if they needed any more information regarding references, etc. No response.
It's now been three weeks since my second-round interview and I have still received no response from them. I consider this rude and extremely unprofessional; I don't necessarily expect a follow-up when I do a phone interview, but if I take the time to come in for an in-person interview, let alone TWO interviews, it's just common courtesy to let me know if you've decided to move forward with someone else. Additionally, I had made it extremely obvious that I was interested in working there (I dropped my salary expectation by 10% just to ensure that I'd be an especially strong candidate), so for them to simply leave me hanging is both confusing and insulting.