I dont know the sony one, sorry. But sony usually produce good phones.
But I recently got the Viewty, its got a really good camera and video (not just from the people saying it does on websites, but from personal experience) Its sound quality is good too for playing music. Not too tinny
It doesnt have much else though. If you are wanting a phone with good internet browsing and lots of extras to fiddle about with, I would go with the Iphone.
Overall the viewty is my fave, and only £120
Hope this helps x