Beauty As Far As The Eye Can See.
Setting foot in Torres del Paine is like setting foot on another planet. You have to rub your eyes a few times to confirm you're not dreaming. It's just you, and nature.
The layers of landscape are so vivid. The glacier lakes are the most soothing shade of turquoise against the variegated, jagged and snow caped mountains. The subtle green rolling hills create the most lovely background for the bursting red of the fire bush flowers. All under a blue sky, a real BLUE sky, with huge soft cotton-like white clouds... And then the weather completely turn on you in a matter of minutes (Well it didn't for us, but it can).
We visited Torres del Paine in early November, staying at the Eco-Camp. I highly recommend staying there if you're planning a trip. The little domes we stayed in are warm, cozy, and magical. The food is fantastic and the guides are very knowledgeable about the region.
I personally would recommend the 5-day trek over the 7-day trek (it seems to be a better value/time spent), but for the adventurers with the time I'd definitely do the 9-day circuit.
Eat and drink all the Calafate jam and pisco sours you can while you're there, because you'll definitely miss it once you leave.