I attended OBA for my JAA PPL and night rating at the same time as The Flying Dutchman and I can both confirm and agree with what he has written.
On the subject of Mr. AT; I carried out my RT examination and skills test with him and found him to be direct speaking and up front (a quality I respect), but not nearly as bad as I had been led to believe. Certainly he doesn't suffer fools gladly and has little patience for those who expect to gain a PPL without putting in the effort. Don't expect to be best buddies if you do something that compromises safety or violates regulations.
I had decided to take all my exams at OBA because I had some prior knowledge of aircraft systems and performance, but had still allowed extra time in which to do so. Even so it turned out to be tough going to get them all done and the last week was difficult. I was one of the people that was sitting my Nav exam the day of the skills test, as Colette mentioned. If you decide to take all the exams while there then if possible allow extra time and don't expect to be partying too much. And remember, factor 50 sunblock is your friend.
I have personally never taken instruction at any other FTO but I don't feel that my level of tuition was less than if I had taken training in the UK or Ireland. I mean we took the very same written examination as european trained students with the same 75% pass mark. The emphasis is on self discipline, and self study in conjunction with the provided lectures. Flying is not all about stick and rudder, when you are solo knowledge is your co-pilot. I would like to extend my thanks to EchoMike on this point - he has imparted more information than is technically required for the exams but which may some day lead to my avoiding arrival at the scene of the accident, which is nice.
On top of everything that has been mentioned throughout the thread I will just add one point. When planning financing for your PPL please remember to add the CAA application fees of about £150 and another £150 for your class 2 medical and yet another £80 in order to have your night rating added to your ticket. For those who intend flying in Ireland I have been led to believe that the IAA frown upon PPL night flying here, anyone care to clarify this?. It's a shame if that is the case as this was the most enjoyable part for me of flying in the US.
(Welcome home Scottish ladies)