I live to the Southern end of the Chilterns, and yes, it is definitely best ridden on an XC-ish bike; There is plenty of twisty singletrack,especially the Stoke Row/Checkendon/Woodcote end, both bridleway and more ‘creative’ options, but it doesn’t tend to be very technical, apart from wet roots.
North of Henley is very good too- hills are a bit steeper and some great long Bridleway descents.
Cheekyboy- (Or others interested) We have a regular Wednesday night group, loosely affiliated with AW cycles in Reading, as well as some regular riding other nights and weekends. email in profile if anyone is
interested in joining.