Hi Kerrie,
When choosing a Part 3 course, don't just look at the examination criteria as a reference point for your decision. Look at the actual course itself. For example, I passed my Part 3 at Huddersfield University which had two 3 hour examinations on the same day under exam conditions with only JCT '98 (as it was then), Architects Job Book, Architects Handbook of Practice management and an RIBA appointment document.
The course however, was a week long full time intensive course with guest speakers on each subject criteria you are examined on. The course was an invaluable experience. I don't think there is a day that goes by where I don't use something I learned from that course in Practice.
At the time, I felt that the examinations seemed a tad 'unfair' compared with other open book and three day exams within the office. 45mins is not a lot of time to write a essay question about Contract Administration and cite all the relevant clauses etc; however having mentored someone in the past who had to undertake their Part 3 exam in the office, it was clear that they had not had the advice and guidance from their Part 3 tutors / university and had never even been to the University to gain knowledge on any particular subjects. It was expected that our principals had to disseminate that knowledge on their behalf. If you work in an office with many senior people then the advice you receive can often be conflicting and not in accordance with up to date legislation etc.
You need to see what University will give you the most help to achieve the qualification and take a view on which way is right for you. Personally, having known both sides, I would tend to agree with my peer above and take an exam based Part 3 course but one that will give you the tuition and support you need to be able to complete the exam with (realtive) ease.
i hope this helps. All the best. Ian