I have used LAN Chile on a couple of occassions. The first time was when I flew from Iguazu falls to Buenos Aires. I used them again to fly from Buenos Aires to Calafate and the last time was from Buenos Aires to Sao Paulo.
After 3 flights I guess I am entitled to voice my opinion. The first thing I liked about flying with LAN was the fact that I could book my ticket online from a different country. (With Aerolineas Argentinas this was not possible). The site was easy to navigate and the booking and paying for the e-ticket was painless. I also find that other local airlines (Sorry for referring again to Aerolineas Argentinas) charge an additional fee for non-citizens. LAN does not do that.
Check-in was quick and all my details were in the system. Staff were friendly and professional.
The seats are comfortable and the food served on the aeroplane was of a high standard. I was very impressed and surprised when the air hostess (on my flight from Iguazu to Buenos Aires) came up to me and asked me if I was flying with her dad the day before. He told her about me and she came to introduce herself and even offered me an extra food packet (I was backpacking..lol). That extra personal touch meant the world to me.
All-in-all an enjoyable flight experience!