Summary: I have tested this camera for three weeks now. I can only compare this to Canon 40D. The primary reason I bought S5PRO was the dynamic range. The secondary reason was the vivid color. The dynamic range and the film simulation mode are only available when you shoot in JPEG. When you set to RAW, the picture quality is the same as Canon 40D shot in RAW.
Summary: I've been using DSLRs for 4 years now, but have primarily been an Olympus (four-thirds) user. I love the system for its lenses and feature packed bodies at lower price points. However, the one area where 4/3s always had an issue was high ISO and DR; when I read about the S5 Pro, it seemed like the "magic bullet", resolving both these issues at once. For starters, I used the camera for a month and compared it to my to see if I was really gaining anything substantial.