I have a G1 X, and its pretty big, certainly not pocketable, which doesn't really matter to me.. I looked at the MK II in our local camera store, and its much smaller. and might be borderline pocketable. It certainly improves on some areas. It gets rid of that crappy lens cap for one that is built-in. I bought a third party automatic lens cap for the G1 X MK I that works well, but is ugly.
When comparing a G16 with a G1 X MK II, consider the following.
If you want shallow depth of field, a larger sensor is better.
If you want better low light performance, a bigger sensor is better.
If you want a f/2 lens on a small camera with large sensor that does 24mm equivalent at the wide end, your choices are very limited.
If you are like me, and have a issue with big fingers and small buttons, a touch screen is a big help.
If you like to tether your camera to a PC, Mac, or tablet / smartphone, the MK II does that, but not the MK I.
It also has Wi=Fi, but it sounds clunky to setup and use in the reviews.
I almost bought the MK II after playing with it the other day. I sold my D300s today, so I might still do it. The G1 X MK 1 is used by my wife, she does not carry it around, but uses it to photograph her crafts that she sells on Etsy. I'm setting up a bigger place in my studio where she can leave her full sized mannequin setup with backdrop and lighting. I'm trying to figure out how to fit my light table and a computer into the same rather small space (7 X 18 feet with some areas that are 9 feet wide.) She had been using my big 40 foot shipping container this winter and early spring, but moved out when I told her how hot its going to get in the summer. I have a old 66 feet single wide trailer(with heat pump, so its air conditioned) that I gutted to use for my online store - product photography (light table), storage of products, electronics repair area, and a shipping room. Overstock is kept in the 40 foot container. The issue with the trailer for photography is the low 90 inch ceiling, I'd prefer 10 feet or more. That makes lighting more difficult, since overhead lights would hit my head.