I also had the misfortune to find myself at Oxford this week...
There is food all over the canteen floors, waste bins overflowing, toilets with more pi$$ on the floor than down the drain (I can still smell them now just thinking about it), hand towels that are used up by 11am...
I passed the time by asking for a tour of the facilities...can't say I'm impressed, don't know why people say they are the best.
The venue for the exam hall is good with the friendly CAA examiners there, not intimidating at all.
If you want to stay nearby Oxford then stay in the village of Woodstock about 4 miles away. Nice village, lots of B&Bs I've stayed in Regent House B&B for £40 a night. For the £10 extra than Oxford this place will seem like a 5 star hotel. Then you also get the advantage of driving through the security gate without stopping, just wave each day and they think you must be a regular and you can see the look of confusion on their face as they don't know who you are but too embaressed to ask (small things like that keep me amused anyway!