I listened to both the base stereo and the HK one, and I went with the upgrade. The reason is that the HK one has a pretty decent Surround Sound. The base version has no DSP processing. It's kind of primitive in that respect. The HK version also sounds fuller because of better bass and better tweeters. Back in the old days, I would have gone for the base stereo and just do an aftermarket upgrade. But nowadays, the stereo head unit is so integrated into the whole IDrive thing that a replacement head unit would just ruin a lot of the functionalities. The stereo is something you use on a daily basis- so no sense skimping on that.
I didn't get the lighting package because we live in a well-lit urban area. Also- I've never been in a car (any car), and felt that I needed more light.