It can be a lot of information to swallow no doubt. Like PRS, I came from a background with no FMS experience. My first civilian sim experience we learned to do what was required for the checkride, but my flying job still didn't have a FMS, s oevery year was just a rehash of the last. I recently attended a ProLine21 *recurrent*, but it wasn't a recurrent for me since it was all new. This is where I felt that a lack of FMS experience was a detriment. With only two sims to try and get down the FMS while still learning a new avioincs suite and still doing the regular recurrent stuff - it was not the best training in my opinion. 2Stg is correct, at least in my experience, that you can read the manual all day long, but sitting in the sim/airplane and actually pushing the buttons (with some real world scenarios) is the best way to get a feel for the FMS/avionics suite.