i thought they were a blast, but since i dont remember the 64 ones too much, its hard to compare the two
i didnt really feel slowing down too much with regards to the turns tho
it may be the handling on the car i chose or the way i play or something (i used the pink birdo car)
but i thought they revamped the system in a great way to incorporate the boost burst from 64 with the pacing of the original