Sidemount class is epic! I greatly enjoyed mine, but for greatest effect, it's a good idea to do a combined sidemount/intro to tech to really get a feel for the opportunities afforded by the configuration. Most of all, take your time! When I signed up, my instructor grilled me on how much time I would realistically be able to devote to training, and said that realistically around 50 dives would be reasonable to 'really get it' - our class does like 1 or 2 'real' classes every month, then we meet up without the instructor 3 or 4 times during the month to practise the skills learned over and over again. - thankfully we are blessed with free air refills and free access to the Quarry as part of the course.