I like the bar seating. That way I could face any direction that I wanted to. I also like being able to easily see over the top of the railing.

Bench seating, particularly when arranged like the last pic. Much more inviting place to sit back relax and socialize.

If you are already planning to have deep seating, such as chairs, chaise, outdoor sofa, etc nearby, I would prefer the bar seating. Plus the bar could double as a serving bar if you wanted to set it up for that after the grilling was done.

If you all are already used to standing around the grill, the bar would be more familiar and natural feeling for drinks, snacks, etc. With the Kamado, there are more than a few stories on the BGE forums of wood cabinets getting too hot, smoldering and eventually catching on fire if there is not enough air gap all around (including the bottom) and insulation. You might want to consider a stainless steel one, or just be very aware of it. :)

Personally, I would prefer the bench seating since I like my seats to have a back as I find them more comfortable.

I dunno, I think a bunch of guys standing around with their beers would be more likely to sit on an individual bar stool rather than sharing a bench.

I think that bar seating is more conducive for conversation and hanging out with the cook. Also good for admiring the view.

^^ Agree with happy2be.