Saturdays would be better because public transport is much better- it's a joke how early some events start - long before any or most trains go anywhere near the venue. But Sat is parkrun day and for that reason I prefer events on Sundays. I worked Saturdays for a while so did occasionally have to take AL for events, but that's the case for a friend of mine who works Sundays as well. Midweek evening events are great in the summer.
I did it last year and yes I found it hilly. Someone said that they thought it was easier than Salisbury though and I'd flown around that course and got a PB so I wondered if I was just unfit when I ran Tadley! But I'd concur with Nic that the second half was almost continuously uphill. Every time I turned a corner there seemed to be another hill. However, I will do it again as I loved the memento, but couldn't get there this year.
I also agree about the Mortimer medal. Reading RR sorted out a lovely medal for Shinfield this year so why not Mortimer?