There appears to be a big difference in how this blur (called bokeh) is rendered, based on the lens and diaphragm blade design.
Some people are saying that the 35mm is not that nice looking, while the 50mm is good. It's all personal preference.... but me personally, I'd rather get a 50mm and spend the extra money elsewhere.
Like a flash.
Or even a flash umbrella if you want PERFECT pictures of your kids.