The ZS19 is the same as the ZS20, except without the GPS.
I prefer the ZS15 over the ZS19 or ZS20.
The lens on the ZS19/20 shows vignetting, which means the corners of the pictures are slightly out of focus.
And they both use a 14MP sensor, which means more noise, which means a loss of fine detail.
Every once in a while, camera companies put together all the right parts and produce a real winner.
That is the Panasonic ZS15.
The ZS19/20 is a good choice but the ZS15 is a better choice.