bit of a late response but this is a subject close to my heart - the poster who said there are a lot of jumped up ****es - never said a truer word - there are many schools run by hobbyists who may offer cheap rates but their goal is not your goal. the most important question to ask is - Is you instructor paid by the flying hour? most schools schedule 2 hours for a 1 hour slot -this allows take up of slack/overrun and should allow for pre and post briefing. All too often the briefing is cut out altogether
In my experience - both getting myself trained and pushing through friends and nearest and dearest I would emphatically say you have less than a 50:50 chance of finding a good 'teaching' set up in the UK- the smaller schools are often run by a hobbyist proprietor (I know one who is more interested in chocolate bars and model planes:-) and very few who have the courtesy to greet you well when you walk in the door) with instructors on flying time only. The bigger schools are plagued by young 'hours builders' who are inadequately managed and rarely teach well.
I've seen far better teaching aboad - full of care and passion for the student which I have come across only infrequently in the UK
just think also instructing is exactly that - issuing instructions
teaching is understanding how people learn and adapting the scenario accordingly so they understand for themselves
IMHO UK training is appalling and is in desperate need of some business standards or audit.