No experience with the Dorset St office, but having received a present of 10 lessons from a family member (who was passing on lessons they had bought for themselves having passed the test first time) I was very happy with the service. It was nearly 18 months after I received them when I finally went to use them. One call to the Customer Care and they got everything sorted for me (they had to do a search on the purchase as I wasn't given any reference code). I used an instructor in the West of Ireland. They were excellent (though I will admit that I just as easily could have gotten a terrible instructor) and again helped me pass the test first time (the family member having used an instructor in North County Dublin, and again very impressed with the standard). I had a number of lessons remaining when I passed, so again they were transferred with ease. A couple have been used now in Cork and again I'm told the instructor is superb. Maybe I got lucky with the service I received, but from my experience I'd happily suggest ISM to any friends/family. [No connection with ISM other than having lessons with them] (apologies, for some reason the formatting of the post is turning up as a single block of text - was playing around with net settings so have to go look at what I changed)