RX100 - panorama, noise, 5mp setting

Quick questions on the RX100.

1. Would the panorama shots be more like the small sony digicams such as HX9v etc rather than the NEX with its actual shutter? The small digicams do pano more easily and consistently and the NEX. I had both.

2. Noise and DR. Now that there are a number of samples, is there a concensus as to its noise characteristics? In particular, how many stops behind a NEX 5 or 7 is this sensor in regards to noise and DR?

3. With 20 mp which feels like overkill, I can reduce the apparent noise by downsampling to something like 5mp. If I simply set the camera to 5mp, would it do that or do I need to do this via software in photoshop?

Thanks,
MTMT