They're both good brands. I used to have a Tosh, a couple of friends have Toshes, and my other half has a Sony (the S model from the range that you've mentioned). You should also consider HP.
Personally, if it was between the Sony and my own HP, the HP would win for its much better battery life. The Sony would have the edge if all you want to do is keep it on mains power and watch DVDs on it, as it has a nice screen for DVD watching. Don't try to use with a light source behind you in just the wrong place though; that shiny X-black screen is more prone to reflections. HPs and Sonys are generally slightly more competitively priced that Toshibas.