Not a complete answer to your question, but 12c's new look is very good.

We were presenting OBIEE 12c to a customer recently, and our dialogue was something like this:

We: We want to show you OBIEE 12c.

Cust: We already have OBIEE 11g, and we don't like it. It's ugly.

We: Look at this 12c demo.

Cust: Wow!

I know that's not what you want to hear, but “People don’t want to buy a quarter-inch drill. They want a quarter-inch hole.”

From my experience, the best you can do is to show how to solve any of the customers problems. If you come and show tables or charts, nobody is impressed. They've already seen any table and chart you can show. But when you come and show how to solve a problem using these table and charts, that makes wow.

One example. In our BI 11g PoC, we showed to a customer how to visualize a relationship between two of their measures with a scatter view. They could swear there is no dependence. But it was obvious that there is, at least, a correlation, after we finished a presentation. And two days later they managed to understand the causation. That made a bombshell effect.

Don't 'sell on features' ... @Andrewif and @Christian Berg are pointing you in the right direction.  It's about business value and architecting a system that can serve answers to questions about the business when the business needs them.  It's about a system that can facilitate the decision-making process to give people more accuracy and consistency than they had before.  It's about modeling a business process so it can be managed and improved.  It's not about technical features - nice and all that they are.