The Ricoh GRD Line of P&S camera are Top Notch. If I had to pick between the two, I'd go IV, but the III will save a little $$$. The GRD IV with IS would be nice in low light, especially with something so light. The SNAPSHOT function is pretty neat and the ability to turn all the lights/lcd off is great for discreet photo ops. I had the GRD III, but returned it as I really wanted a GR1. From what I have read the 28mm Ricoh VF or any for that matter is okay, as framing was a bit off. Im sure like any VF topped camera, "you" have to get use to the spacing/capture.
One P&S I do miss from the few I have had is the Olympus XZ-1. A great camera, with bright lens wide: f/1.8, Telephoto f/2.5, but man is it sharp.
The Dual-IS, what ever it may be, is Very Nice as well. The ability to use a EVF VF2/VF3 is pretty neat too. I had a VF3 mounted and it did help with framing in the bright afternoon sun. The LCD was pretty hard to make out with reflections/sunshine.