Compared to wiiU
In handheld mode the GPU is like a wiiU plus (think 3DS > NEW 3DS) but has the benefit of 3x the usable ram, a significantly stronger CPU, and an architecture about 5-10 years newer (yes I realize that's a wide gap but the architecture on the wiiU was a weird hodgepodge of older and newer).
In docked mode its about 4x the wiiU's GPU with the previous benefits.
Compared to the Xbox One
On paper it's GPU (docked) is a bit under 1/3rd the Xbox One (which actually isn't a huge gap) but it once again benefits from a newer architecture (about 5 years newer), a CPU that is weaker but not signficantly, and about 64% of the usable ram (3.2GB vs 5GB)
Compared to the PS360
10+ year advantage on GPU architecture
About 4-5x the GPU power (docked)
A significantly better CPU than the 360 but not the Cell (the Cell can still outperform the PS4 CPU in some tasks)
6.4x the usable RAM
In practice what you'll probably see is PS360 era graphics running at 1080p 60fps and a few improved effects.
Or 1080p 60fps PS4/Xone games running at 720p 30fps.
Examples we can point to are
Snakepass
sub 900p 30fps PS4
Switch Sub 720p 30fps with a few effects removed
Lego City Undercover
PS4 1080p 30fps/60fps
Switch 1080p 30fps
The Switch also managed to get a full Physically Based Lighting system over the wiiU version, higher resolution shadows, longer draw distance, increased texture resolution, 1080p docked, and a more consistent framerate in this game.
In handheld mode the GPU is like a wiiU plus (think 3DS > NEW 3DS) but has the benefit of 3x the usable ram, a significantly stronger CPU, and an architecture about 5-10 years newer (yes I realize that's a wide gap but the architecture on the wiiU was a weird hodgepodge of older and newer).
In docked mode its about 4x the wiiU's GPU with the previous benefits.
Compared to the Xbox One
On paper it's GPU (docked) is a bit under 1/3rd the Xbox One (which actually isn't a huge gap) but it once again benefits from a newer architecture (about 5 years newer), a CPU that is weaker but not signficantly, and about 64% of the usable ram (3.2GB vs 5GB)
Compared to the PS360
10+ year advantage on GPU architecture
About 4-5x the GPU power (docked)
A significantly better CPU than the 360 but not the Cell (the Cell can still outperform the PS4 CPU in some tasks)
6.4x the usable RAM
In practice what you'll probably see is PS360 era graphics running at 1080p 60fps and a few improved effects.
Or 1080p 60fps PS4/Xone games running at 720p 30fps.
Examples we can point to are
Snakepass
sub 900p 30fps PS4
Switch Sub 720p 30fps with a few effects removed
Lego City Undercover
PS4 1080p 30fps/60fps
Switch 1080p 30fps
The Switch also managed to get a full Physically Based Lighting system over the wiiU version, higher resolution shadows, longer draw distance, increased texture resolution, 1080p docked, and a more consistent framerate in this game.