My favorite thing about this episode actually doesn't have anything to do with Cases or Maps. I love the moments with Rose & Charlie. I love how Charlie is just sitting around mopping and Rose starts telling him to get off his bottom and start helping. I also love the conversation about Faith and how she tells him that theres a fine line between faith & doubt. Of all the dead Losties I miss Charlie the most. I love his character. I also hope that we bet a lot more of Rose next season.
The Gun Case stuff was interesting, I loved the talk between Jack & Sawyer, there was still the tension between them from the torture and their personalities, but there was also a moment near the end where you could see the start of the friendship that Sawyer alluded to near the end of season 2.
The moment when Jack was pressuring her about the plane and she burst out about it belonging to the man that she killed was such a great moment and it alluded to the future episode where we find out about her childhood sweetheart the doctor that got gunned down when she was trying to escape a hospital.
As for the translation of the map, it didn't really go anywhere and I never did like the Sayid Shannon relationship. I could better see Sayid & Kate together. But I'm actually wondering why the map hasn't been used anymore up till now. If the small island is on their (freeze frames can be found on the Internet if you look for them) wouldn't New Otherton and some of the Hatches be on there? They could have found them sooner. Maybe in seasons 5 or 6?