I had a great time on the river walk despite the freak cold front! It was under construction when I went so it was a little difficult to walk around especially when you have a group of people. There are lots of little shops and tons of restaurants and bars and not just touritsty places. Make sure you stop by the Alamo across the street first and there's usually street festivals and music going on there as well.
Don't get too close to the water, there aren't many guardrails but there are bridges and the sidewalks are pretty large. It is very clean, but pretty crowded as there are a lot of groups getting in and out of river taxis. You'll get a lot of people asking you to come and have a drink, but it's not that annoying. A must go if you have the time!More