Considering the amount of miles (and not to mention $$$) once has to fly, I think the 30% bonus miles is a little stingy.
If SWISS joins Oneworld (eventually), I take it that CIRCLE will compete with CX's MARCO POLO CLUB as one of the most difficult to achieve as EMERALD. Mind you, from zero to EMERALD on CX, you'd need about 210K miles in a year (or spread over 3 years - one for each level). But no bonus miles for flying on CX/Oneworld flights, so maybe SWISS edges out MPC.