I strongly dislike fully articulating screens. I still use my Panasonic G9 because of its other features, but the FAS is a constant source of frustration and definitely the worst thing about the camera. If there was a tilt screen special edition of the G9 for an extra $1000 then I'd buy that without hesitation.
I primarily use the screen rather than the EVF. That means I end up with the FAS stuck out the side most of the time, otherwise I'm constantly flipping it out and back whenever I want to take a shot.
For me the main disadvantages of a fully articulated screen are: the stuck out screen getting in the way, loss of touch screen functionality, the extra steps when switching between screen and EVF, the increased problem of glare from the sun, and how awkward it makes holding the camera at a low angle.
I shoot a lot of macro, sometimes poking the camera into undergrowth or trying to get unusual angles close to subjects. Having a screen sticking out and practically doubling the width of the camera can make life more difficult. It's also a fairly fragile part of the camera to have sticking out while carrying it.
I love being able to quickly set the focus point using the touch screen. I find tapping the screen much faster than using a D-pad or joystick to move the point around. On a tilt screen that's always within reach of my thumb, while a screen stuck out the side isn't so easily accessible.
Tilt screen are obviously quicker to deploy than a screen that has to be swung out to the side. I can adjust the angle of the tilt screen while still keeping my hands on the lens/controls. The tilt screen cameras I've used automatically disable the EVF eye sensor when the screen is tilted, or at least provide enough of a gap that it isn't accidentally activated. I can tilt the screen for a low level shot, then simply push the screen flat with my thumb if I do want to use the EVF again. With my G9 the eye sensor needs to be manually deactivated or it constantly switches to the EVF when I'm trying to use the screen.
Having the screen tilted behind the body of the camera solves the issue of sun glare in most situations. Between my body/head leaning over the camera, my hands to the side of it, and the body of the camera itself, the tilt screen is pretty well shaded from the sun 99% of the time. A screen stuck out the side of the camera is often washed out with glare in the same situation.
I take a lot of shots at low level, especially when shooing macro/wildlife. Even if my knees didn't complain when getting back up again, I'd rather not go lying in the dirt if I can help it. With a tilt screen I can keep a comfortable stabilising grip on the lens even when crouching down and holding it at ground level. I can't see any way of doing the same when using a camera with a screen stuck out the side. To avoid blocking the FAS while supporting the lens from above, I have to hold my arm out to the side at an awkward angle. It just makes that kind of shooting slower and less comfortable, requiring a faster shutter speed to compensate for worse stability.
Obviously a fully articulating screen does have advantages, e.g. when shooting vertically, but for me the advantages of a tilt screen massively outweigh the extra FAS flexibility.
