PAL generally runs on an 8MHz channel, and encodes colour in an entirely different way (each alternate line is reversed, meaning that small errors cancel out - where in NTSC you had a "Tint" control to adjust to any errors).

PAL also requires considerably more accurate and consistent color information. NTSC displays will usually take almost anything close and display it.

See the Apple 2 video circuit for a great example of that.

Hence "Never Twice the Same Colour"

With high persistence phosphors, PAL is nice. The higher frequency color makes a notable difference.

50hz was often just a bit slow for me. PAL 60 is where it was truly at, IMHO.

Both formats have nice abuse potential, and exploiting it on early computers, and later on, microcontrollers, is a lot of fun.