The 20.04 Standard is a closed cassette with a basic 1:4 drive (only), the 20.09 Bespoke is an open cassette and has the choice of a quality 1:1 or 1:4 drive.
The 20.09 Bespokee also has the Easylock spool (No screwdriver required)as standard. The 1:1 & 1:4 pullaway drives can be used in both headrails.
The price of the 20.04 Standard is less than the 20.09 Bespoke.