Size and weight are big decision factors when you are trying to find the ideal camera for your needs.
In this section, we are going to illustrate the Sony TX66 and Panasonic GX7 side-by-side from the front, back and top in their relative dimensions. Sony TX66 has external dimensions of 93 x 54 x 13 mm (3.66 x 2.13 x 0.51″) and weighs 109 g (0.24 lb / 3.84 oz) (including batteries). Panasonic GX7 has external dimensions of 123 x 71 x 55 mm (4.83 x 2.78 x 2.15″) and weighs 402 g (0.89 lb / 14.18 oz) (including batteries).
Below you can see the front-view size comparison of the Sony TX66 and the Panasonic GX7. Sony TX66 is clearly the smaller of the two cameras. Its body is 30mm narrower, 17mm shorter and 42mm thinner than Panasonic GX7. As you can tell, actually this is not a fair size comparison since Sony TX66 has a built-in lens but Panasonic GX7 doesn't. Once you put a lens on GX7, its thickness will increase significantly.
Here is the back view size comparison of the Sony TX66 and Panasonic GX7.
Now lets look at the top view comparison of Sony TX66 and Panasonic GX7.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Sony TX66 is significantly lighter (293g ) than the Panasonic GX7 which may become a big advantage especially on long walking trips.
Again, this comparison may not be very useful in real life as we are comparing the weight of a camera with a built-in lens to the body-only weight of an interchangeable lens camera. Once you put a lens on GX7, the total kit will weigh much higher.
Weather Sealing
Unfortunately neither the Sony Cyber-shot DSC-TX66 nor Panasonic Lumix DMC-GX7 provides any type of weather sealing in their bodies, so you have to give extra care especially when you are shooting outdoors. If weather sealing is a must-have feature for you, check these sections: Top Compact Cameras with Weather Sealing Top Mirrorless Cameras with Weather Sealing
LCD Screen Size and Features
Sony TX66's 3.30" LCD screen is slightly larger than Panasonic GX7's 3" screen.