Balds, did both last year. Wokingham has 3 or 4 bridges to go over with short inclines, whereas Reading has 2 proper hills, not that long or steep, but more than Wokingham.
I came about 1min 20 slower at Reading than Wokingham, but i fairness, I built up big to Wokingham, and the effort caused me to lock my back, so had to sit a week out, and when I came back it was all a bit after the lord mayor's show.
Some people argue Reading is faster, and although I can't see that, maybe if you attack the downs and work it on the ups you can use the much bigger crowd support and epic field to take you home quicker,