In comparison with a Pi 5, the slowest of the above, which is the X2L/Palmshell kicks the butt of the Pi 5 six ways to Wednesday. Just so much better, it's unreal. Web-page resizing works immediately, video plays well, it just feels like a real PC, even though it's a bit slower than my EliteBook, which is still pretty handy.
Not got an X4 yet, but from the link above, it should be about 50% faster than the EliteBook, which in turn is 50% faster than the X2L / Palmshell.
Not got an X4 yet, but from the link above, it should be about 50% faster than the EliteBook, which in turn is 50% faster than the X2L / Palmshell.