For stills and video in little packages, the combination of the RX100 and the GW77 can't be beat, with one for stills, the other for video, however.
The RX100 is really not a good video camera. This is from the RX100 manual:
"If you use a function such as zoom while shooting a movie, the sound of the camera operating will be recorded. The sound of the MOVIE button operating may also be recorded when you press the MOVIE button to stop recording."
I cannot believe they cannot make a silent movie button for the Sony cameras, as on all Sony Handycams. The Sony Nex-5N has this same problem of the clicking movie button. It means you have to edit every clip - it is very annoying if left in at the end of every scene in a video.
The GW77 movie button is completely silent.
There is a second limitation to the RX100 zoom, besides it making noise (which is unacceptable) - the zoom speed is not variable in movie mode. The GW77 zoom is variable, depending on pressure, and completely silent. If one zooms during video, having the ability to control zoom speed is critical.
And there is this - you cannot turn off digital zoom in video, and there is no indication when you have gone beyond optical:
"During movie shooting, the digital zoom always operates when the zoom scale exceeds 3.6×, even if [Digital Zoom] is set to [Off]."
This the degrading digital zoom (as the manual says), not the good one:
"[Clear Image Zoom] is not available while recording movies. The camera zooms slowly while recording movies."
Clear image zoom is used in video for the GW77; you can turn off (the default) digitl zoom on the GW77.
And, of course:
"Continuous shooting is possible for approximately 29 minutes at one time at the camera’s default settings and when the temperature is approximately 25°C (77°F)."
The maximum continuous recording time for the GW77 is 13 hours! I don't intend to make a 13-hour contiuous movie, but I can foresee some events that require more than 29 minutes.
With the limited zoom range - less than 4X - and the high minimum f-value in telephoto - much higher than the GW77 even at 10X - and these other noise and zoom issues (plus no control of audio level, unlike the GW77), I have been turned off the RX100.