Having done the OAA integrated course - I would broadly agree with most of what has been said. However anyone who thinks that the training in AZ is excellent is either nuts or was very lucky. Generally the standard of instruction there was poor (although it did improve post CPL skills test) in my experience. The instructors were badly controlled (probably due to the director having been sacked without replacement) , some turning up when they feel like it, or just not turning up at all. Many taught their own flavour of aviation rather than the OAA syllabus. Scheduling and maintenance is hit and miss. Communication with the students is dire. The aircraft (and there can be no debate on this) are decrepit. One PA28 in particular looks like it was the subject of an arson attack. The PA34s generally had an availability of 2 servicable aircraft out of 7. Say what you like about "that's aviation" but the fact is that this is a very expensive course and I think its unreasonable to have to use a fleet of aircraft which could easily feature on scrapheap challenge. They all have different avionic fits, having mostly been sourced on the cheap from different sources.
That said, groundschool in the UK is excellent. The IR training in the UK is also very good although the instructors feel that they are having to spend the precious few hours re-teaching what should have been taught in the US. The MCC/JOT is top line.
I now wish I had gone elsewhere or gone modular. I probably sound like a bitter old tw*t, but I did manage to get a job and I suppose they must have done something right, but the overall experience didn't live up to 50% of the expectation...