Oxfordman,
You have very quickly jumped to the wrong conclusion with your assessment of BFC, they are a very good school with an excellent reputation for IR training in the U.K. Some of their instructors are first class & they can see exactly what is required to obtain a first time IR pass in min hours.
Quote: "Roy was very adamant in trying to sell me an IR conversion at 10 multi/5 sim instead of the above"
That is a no brainer, more time in the aircraft is a real bonus, regardless of your 'wealth' of experience; 5 hours to experience some of the procedures at Bristol, familiarise with the aircraft, fly a couple of routes & get up to speed for the U.K JAR IR is not enough.
BFC are not interested in trying to make max money out of you & if you are as good as you 'think' you are then you will have a IR in 15 hours, I know plenty of people who have gone through BFC in min hours with full support of the school to take the test in min hours.
Surely honesty is the best policy, Roy has tried to give you realistic advice, would it not be worse to say to you yea no probs you will be done in 15 hours no worries, but then after 20 & a failed IR test you would be quick to moan then!! Do you know how much it costs to take an initial IR test inc aircraft hire to then fail & re take? I think you will find a couple of hours extra training then a first time pass is better in the long run if you are not ready after min hours.