I did the 50km one and it was well organised. Decent course for a race with lots of riders.
It wasn’t a technically demanding course and not “racy”, everyone was having fun and most were just riding their bikes. Faster riders politely overtook me. Those I rode along with were full of bike banter. Decent mix of types of rider / bikes.
All in all a good day out.
I did the one near Wantage, up on the downs. Some mates of mine did the 75km route and said the extra bit was a bit too much road and next time would stick to the 50. There were tiny bits of small back lanes, but mostly good double track and the odd bit of single track.