Do you have any advice for potential travellers?
Some of the hikes are pretty tough - if you have a chance to do some walking/training before you go it will definitely help on a couple of the days and the views are well worth the effort. Other options were provided to those that didn't want to do the full trek though. The optional walk on day 8 to Cerro Cristales is tough (the trip notes say that this is 'not a difficult trek' but it's steep with a scramble at the end on scree and I thought that was overselling its ease!) Be prepared for all weathers. We were mostly blessed with great weather but even so used the whole range of clothing from tshirts to fleeces and waterproofs.
Make sure you have a padlock for the lodge at Torres del Paine. Also don't pick the top bunk if you can help it and if you DO have to, pick one next to a pillar for additional leverage when climbing in and out. They are the highest bunks I have ever seen (I am 6 foot tall and could not reach up to put things on my bed) and they have no handles to help. Spectacular tumbles have been known to occur even before Christmas tipples were taken!
You don't need to change any money for Chile - you can use USD in the lodge and you won't go to any other shops. Also in spite of advice that you need to pay cash for the options, it turned out that credit cards could be used.
Take lots of insect repellent and your choice of anti-histamine - I got bitten at the airport on landing in Buenos Aires and took bites home with me at the end. Part way through my eye was so swollen I couldn't open it. Never saw any of the little blighters though....Go to the tango show. I honestly thought it would be the tacky touristy end of the holiday but the meal is great and the show was brilliant (if you can turn a blind eye to the flag waving in the rendition of 'Don't Cry for me Argentina...).