There is quite a few of those high end compacts around these days.
In general you can divide them into the larger and smaller sensor group.
Larger sensor ones are the Nex series, the Canon 1G X and Fuji x100. All 3 are quite different cameras, but similar in Image Quality.
NEX has changeable lens, no viewfinder.
Canon has fixed zoom lens, viewfinder.
Fuji has fixed prime lens, viewfinder.
For myself a viewfinder is an absolute must. On such a compact I would not want to carry several lenses so I would be ok with a fixed lens, itdoes not need to be interchangeable.
So in that sense the Canon would be the better choice - it has the viewfinder and the required zoom lens.
Note that all those cameras are size wise too large to put into a pocket, so you still will need to carry it in a pouch, bag or on a neck strap.
Nikon, Panasonic and Olympus use smaller sensors in their high end compacts and image quality is a notch below (at higher ISO with less available light, at bright days with [plenty of light they do as good as Sony, Canon and Fuji) but still very good overall.
Same goes for those cameras however, the models with viewfinder and zoom are the larger ones and if you mount a zoom certainly not pocket size anymore.
So at the end of the day look what lens you want to use (zoom/prime lens) and if you want a view finder or if you are ok shooting all the time using the LCD in the back. Decide from there.
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