Firstly, the behavioral interview is much like any other interview, asking how one would describe judgment, strengths/weaknesses, how you deal with mistakes, etc.
The case interviews are mainly geared to seeing how you will deal with ambiguity and problem solving, but mainly ambiguity. The two cases are a ski hill problem were you must figure out the number of customers through the capacity of the chair lift in order to determine revenue, then provide recommendations of how the company should re-capture their customers from a competitor. The second case was how to motivate individuals, determine company culture, and improve outlook on employee reviews. In many instances during both cases, when asking for further information they answer that they don't have the data or don't know; so it is really getting at how to think around the problem and provide them with details and definitions of management and marketing terms rather than broad ideas.
Thirdly there is an interview with a "partner" which really just means an interview with a senior member in the company. This is were I would recommend interviewees have more company based questions about operations, support, culture, where the company is going, etc.
Finally the dinner, although the plates are more expensive, it's really geared towards understanding the interviewee at a more personal level and how they interact in social environments. This is when you really want to know all senior management, their background, etc. as the two partners and some senior level employees will definitely be here. They open up the forum to ask whatever you want, so be able to ask some smart strategic questions to get to know more about how senior management thinks and how the company interacts as a whole.
I ultimately decided that Arryve was not the right fit for me at this time, but they are a very energetic, driven, straight-forward, honest crowd. From my experience one must have a thick skin to be able to positively accept critiques almost constantly and be able to thrive in a very open environment.