We went in May, and we did the 1pm Wild Africa Trek, it was AWESOME.
The 1pm was pretty great for a couple reasons. We were able to do everything we wanted in the parks before the trek, with very minimal waits (it was the morning after all). The trek (and showing up a little early for it) took up the busiest portion of the day. By the time the trek was over it was late afternoon and once again there were almost no waits for anything, we were able to ride EE over and over again
But the trek is fantastic !