Check what length stem the full builds come with, also bear in mind the bars are pretty wide at 800mm and check if the seatpost has any offset (last years giant ones were circa 25mm!). So swapping to a shorter stem and a more sensible width bar and a inline seatpost (unless one was fitted to the bike you tried), the large will feel a little smaller.
bluearsedfly, I’d say you were more of a medium than a large, especially if you are using it for everything. FYI, I am 6ft with a 33″ inside leg, I have a large with a 40mm stem and a 780mm bar, 170mm dropper (with seat slammed forward in the rails to get weight over the front for climbing)