I would agree with you that Sundays can be conducive to better service on average. At least that has been my experience. However, since Sundays are not convenient for me, I find that weekday mid-mornings or mid-afternoons also result in more attentive ladies (i.e. avoid the lunch time or after work rush). A lot depends on the ladies themselves - whether they're an early starter or a strong finisher. If I can, I try to a catch an MPA early in her shift.