No it doesnt. Seems that 500mhz is the optimum idle clocks, because
1. It runs with very low voltage (lower than what 250mhz normally uses, actually my 500mhz mode uses same voltage as the 125mhz mode would use by default)
2. Phone is noticeably faster with less jerking. (than with 250mhz, 125mhz idle is just plain horrible)
3. After 500mhz idle clocks I havent noticed any considerable speed up of things (because Im still using 500,805,1000,1100 steps)

Oh and it feels more responsive with less clock steps, therefore I only have 4.