Not a lot - goes on.
There is a rumour that Oxford is no longer all that GA friendly.
There is a reasonable amount of training some of which departs airways and not a lot else.
The surrounding airspace is not particularly busy other than sunny weekends when every where is busy.
I visit Kidlington quite regularly. The new GA terminal is wonderful and they should make an effort to be more GA friendly, lest so many airports forget that the executive jet traffic can disappear as quickly as it came, as can all the intense young students and the CAT.