For a daily driver, the YF is better. Much better metering circuits in the YF. The only real problem with the YF can be the diaphragm type accelerator pump. If driven only occasionally, the gasoline in the bowl can evaporate, leaving the inside of the carburetor dry. Diaphragms don't like to be dry once they have been in gasoline. They show their displeasure by becoming brittle and cracking, rendering them useless.
The W-1 is a much older design (1932 vs 1950). Accelerator pump is the much preferable leather. After the leather dries out, simply refilling the carburetor with gasoline will soak up the leather, and the accelerator pump will perform.
Personal opinion - on a scale of one (awful) to ten (wonderful), I would rate these as follows:
1932 - 1933 W-1 (5)
1934 - 1936 W-1 (5.5)
1937 - 1948 W-1 (7)
1949 W-1 (7.5)
1950 up YF (9.5 if used as a daily driver, otherwise 6)
1950 up Rochester B (5)
Jon.
