Interviewing with Uber was definitely the most pleasant experience I've ever had. To describe it in one word, it was concise. It was shorter than most interviews I've been to, but at the same time the questions were right to the point and there was virtually no overlap from interviewer to interviewer.
I thought the questions were very reasonable. It was not a stressful experience at all. The questions weren't necessarily hard, but they were very intentionally broad/vague such that you had the opportunity to go as deep as you wanted in the interview.
There were no riddle-like questions (ones that were trivially easy once you knew the solution but would otherwise be difficult). This was a good thing and much appreciated.
Everyone I met was really nice and they all seemed like really cool people to me. I left the interview very much hoping that an offer would be extended, so all in all I'd say they did an excellent job.
Furthermore, I think the recruiter was on point. This person was extremely prompt, and I generally moved from one part of the hiring process to the next with just one day of turnover. It left me feeling like the company actually cared about me and wanted to hire me.
After the interview when we talked compensation, I told them my current salary and what I was hoping for with a job transition. The offer they made I felt was very generous and met my expectations, and I believed the recruiter when I was told that Uber was trying its best to accommodate my requests.
I made no counter-offer; from what I'd read on Glassdoor already I didn't think they'd budge on salary, and RSU's were generous, especially given Uber's current state and growth. I also found out they give bonuses, so I was less concerned about what their initial offer was composed of.