Sphinx,
I think you have slightly misunderstood the point on sim practice. Any preparation is, obviously, good. However there are many who, for a variety of reasons, can't achieve a sim slot for practice.
My point was that there are alot of applicants who put themselves on a nervous footing when they are confronted by the complexity of the 747 simulator, cosy as the cockpit may be. If you can't or don't want to invest in a full simulator session then familiarisation with the basic Boeing setup can be done through Flight Sim. In the dim and distant pass sim assessments were done on the BAC 1-11, how did the non-whizz kids get their passes on that, BAC 1-11 sims are as rare as hens teeth!
If you get to the sim you are expected to have the minimum requirements, flying wise, required to adequately pass an initial assessment. If not you won't even get to the interview. Therefore, if you go to the sim and can't or don't have the opportunity to go to a 737ng sim, familiarise yourself with the cockpit layout of the 744, (airlinephotos have good cockpit piccies), have a look at FSX (geeky but useful for the MDU) and relax, you should be able to fly an aircraft by now!
If you want to do the sim practice then I'm sure it's money well spent, have fun and enjoy! It is not, however, a necessity.
Good luck to all.