I bought Stage 2 Interior back in January, '12. Thought they were cool as heck. So, bought Stage 3. Light-wise, they are even better. But, the one thing that bugged me about them came true. Stage 3 are bigger boards with more lights, so heavier. They don't stick. The sticky stuff is plenty sticky, and the lights are great. They just don't have as much area to stick to, where the Stage 2, you just pressed hard, and they took. I had someone who knows zero about cars comment about them, so you can see 'em laying in there. Still, if you need light after dark, these get the job done, no question. (was never able to get the door lights in, maybe some day... If I sell, I'll put the OEM back in, and throw in the Stage 2 and 3 kits as an "Extra"!!)
6/25/12 Edit: This is mostly about the Map Lights. The Stage 3 don't fit as well as Stage 2. No flat surface to press them onto. The little bit of flat plastic housing/surface that the Stage 2 could partially rest on Stage 3 board is too big to fit in that recess. I've tried 3 times. you have to press them onto the two little ends of the metal prongs, and it's not enough surface for them to stick to for more than a few days. (My forester doesn't ride that smooth for a new vehicle either, but that's another story) The boards are plenty sticky. Again, the light is great. You could read a book in there at night, and not strain your eyes too much!
I don't know if you're still using these, but my suggestion, since i just put in the stage 3 kit on my 2012 is to make sure that you pop out the map light diffusers to get the most mounting surface. I'll snap a few pictures to show you what I did. I would estimate that I was able to get approximately 50% of the backing to stick to a flat surface.
As far as the door lights, IMO, they were about the easiest. Lie on the ground with the front door (either one) open above you. Use a small flat head screw driver or similar panel tool and work the plastic housing off. Once off, it is a clip style light, pop it out along with the quick release clip, and put in the same style light from DD, ensuring that the one sided (I think it's two LEDs) lights are pointed out towards the car, reconnect the clip, pop it back in and your done.