I can directly compare (almost).
My miswah (Mrs) has this:
It's the 208 GTi, which came a close 2nd to the ST in all the reviews and the GTi is just as fast as the Ford Fiesta ST.
And I have this:
A BMW E46 M3 CS.... (My 2nd M3)
Right the little hatch back has a 1.6 litre turbo motor the same as a ST Fiesta again producing 200HP. It is well built with nice stylish touches and also has a mountain of torque. Around town it's the perfect car, light on it's feet, small and really fast. It's even fun on the open road with twists and turns and really does like to be chucked about. How does it compare to an M3.
IT doesn't!!!!!
The M3 still feels like a 50k car and the quality of the materials really good. He driving position, the Nappa leather clad sports seats are really supportive. What the M3 has which a lot of cars don't have is that "sports car" feeling. It "feels" special even going slowly. It's direct with decent feel and when driven in anger really shows what it can do. It's a proper performance car. It's much faster than the GTi. The E46 M3 rivals cars like the Audi RS4 and Porsche 911.
Both great cars and I enjoy driving both.