HappyBandit,
I know people who've done both sim rides, the trainee sim is in no way harder. The D/E sim is the same as the trainee one to start with, but where the trainee sim ends the D/E guys have to go around and come back for another approach (NPA). May also be some extra handling involved.
I know this is a rumour network but would be good if ppl get their facts right before publishing on here.