Keep in mind, it's hard to control 2 Ipads from the front seat. We have Ipad in wife's X3. I rather have theater package than two Ipads. Also, you need to remove Ipads when you leave the car. People will break and steal that so easily.
We've had three vehicles with entertainment packages. By far, this is the best of the three. We don't use it often but it is nice to have it if we are traveling. One thing we noticed with one of the kids we baby sit on occasion is that one child can watch a DVD and the other gets car sick more easily. What its good for is when your stuck waiting at the cell phone lot at the airport waiting for a delayed flight. I like the ability to watch something on the front monitor when parked. Finally, since we wanted a luxury vehicle, it just didn't make sense to not fully load the car. The payment difference wasn't that much more. It is a personal choice and if you really don't think you'll use it, I don't think you'd get much more on trade-in down the road. As one of our members has mentioned, you can buy two nice IPads for less money.
I opted out of the theater package. I didn't like the idea of having a big fat tv screen sitting behind my head. I also didn't want my kids dependent on a tv. If we go on long trips, they can use an ipad or portable dvd player. It's really personal preference and whether the cost of the theater package is worth it to you.
I got the package...doesn't it come with upgraded Bose speakers as well? That alone is worth it. I know the sound engineers that worked on this car. The upgraded speakers are so fine tuned and really sound awesome. It's amazing the research and tweaking Bose does for car audio!