I took about 20 lessons with BSM but that was probably more than enough. By the end, it was more of a social outting than a lesson as I got on with my instructor really well and he was a great teacher. Plus, his wife of many years had left him half way through my lessons so we gabbed quite a lot in between him telling me to stop 'palming' the wheel during turns.
But having said that...I needed to learn stick properly (tried in the US years ago from a BF and failed miserably); I never drove in the UK before; I hadn't even driven for 6 years; I needed to unlearn nearly 20 years of bad driving habits.
I was terrified on my test...especially since my learning car was traded in for a new car the day before my test. I was the first pupil to drive it...*on my flippin test*!!
Thankfully I was able to calm my nerves enough to pass on the first go. Only had one minor on the whole test and that was for clutch control when doing a turn in the road (where the road cambered on the sides). Hardly a surprise as the clutch just wasn't the same as what I was used to. I am just *so* glad it's over and done with! Now I just need be careful and not get any speeding tickets and have to take it again!
I thought I'd only need a handful of lessons but was quite surprised by what was expected on the test (Reversing around a corner? I'm sure that must be illegal in the US). I'm sure you'll be able to get a refund if you over-book.
Good luck!!!