My wife and I have just enough days in the Torres del Paine area to do the W trek. But we are not sure if it would be better to do a day hike or two and then some kayaking instead. Any opinions on which is best?
I would have to second that about the W. The park is one of the most naturally beautiful places I have ever seen in my life and the trek was simply amazing - a highlight of my journey to South America.
The diversity of the natural environment is what I think made the trek so unreal. You see glaciers, mountains, forests, streams, fields, lakes, rocky areas, wooded areas everything in the space of a few days. I wonder how much of this diversity you would miss by just doing day trips.
If you're physically capable - Do it!
It's one of the most amzing things I've ever done. But prepare yourself - nights are cold and can be rainy so get good sleeping bags and a good tent. The camp sites cost money (in addition to the entrance fee, super annoying, I know) and in most of them there is no fireplace so bring a mini stove (or whatever its name is..). There's also accomodation in the park and along the trail, they're pretty expensive from what I've heard but it will save you the trouble of carrying everything on your back.