I think that even the 020 on the Amiga 600 is to much.
Before starting to consider an accelerator i was using the A608 8mb fast ram board an i think that 1 extra mb of chip ram is also a must on the A600.You can play some AGA games as well with 2mb chip ram on esc they also work on the A500 as well.So having a fast processor like you say and lucking a better chip set witch might utilise it is just not practical.
There are some apps that will require 020 to run like iGames but again is it worth in on the A600 ? I think not
So in my mind and wallet the best A600 setup = 3.1 rom , 8mb fast ram , 2mb chip ram and a nice CF disk > ESC optional ( This way you can play 98% of Amiga games on WHDLoad ) and the system will be stable 100%
Are A1200 accelerators worth the trouble ? i think ill get an A1200 in the near future....