It really depends on your intended use and goals.
I don't have experience with the G7, I did however start out with a TG-4 and after 2 years switched to an rx100.
The tg series are great out of the box for macro, but can be limiting for wide angle and depending on your expectations the small sensor might become limiting.
Despite upgrading fairly soon I'm glad I have my tg-4 as a backup/snorkeling camera and don't think it was the wrong way to start out in uw photography.
