- Easy, intuitive operation (no PhD required)
- Totally weather sealed (at our studio event I poured entire cups of water all over the S2 - several times, actually)
- Faster glass (f/2.5) that is actually sharp into the corners wide-open, with no vignetting (and not needing s/w correction)
- Much, much faster image processing (instant zoom, scrolling, etc)
- Bright, large, high-res LCD vs. any other MF system (easy to see outside and easy to gauge sharpness)
- Great color out of the box (even without profiles) and already works with a wide range of software
- A full pound less weight (with standard lens and battery)
- The same size as a 5D with image quality at least as good as any 39/40MP system
- Nicer viewfinder that makes manual focus easy (without a 3x loupe)
- Long, long battery life (over 1000 shots or >70GB of RAW files)
- Dual memory cards with mirroring for extra security
- First MF to offer FP sync up to 1/4000th with hot shoe flash
- Lowest mirror vibration and best overall dampening of shutter (check out at Mark Gowin's shot of Greek restaurant interior - 1/3rd of a sec, propped up with napkin-wrapped silverware on a 4-top table)
Did I leave anything out?
I think David K summed it up nicely when he said, "The S2 gives image quality as good as my Hy6 with my best lens, with less post processing work, in a size I'd actually want to carry."
Don't take my word for it. The best way to see the difference is to try it for yourself, especially next to other MF systems.