Having recently undergone 'reprogramming' to become a civilian ATCO( I self funded a Surveillance rating course), I have experienced next to no difference in terms of exercising the function of controlling aircraft. Yes, there are subtle differences in the way that 'control' is exercised but not to the extent that I found difficult to adapt to. Sure, the equipment used might be different in appearance but the functions remain largely the same. In short, there is next to no difference between the 2 domains and to be frank, I found the course a doddle(apart from picking up the training tab at the end which was extremely difficult!).
My advice would be to approach the course with a willingness to abandon your previous experience and start back at square one; ditch any airs and graces you might be saddled with; and when you get to your unit say nothing and just do as you are told. All towers have politics, and mostly the same issues exist; the only difference is that nobody wears the same uniform!
The military are currently critically short short of ATCOs (particularly the officer cadre who are leaving in droves) are it is not in their (MoD) interest for the grass to appear too green over the fence or for the process of conversion be too easy to achieve.............