Bookworm, as mentioned the type on the fpl and thus shown on the fps is not 100% reliable.
As the type is significant to safety, in my case an example might be tucking an A320 2.5nm behind what you thought was another A320 but which turns out to be a B767 and you hadn't bothered to check when the type wasn't given...well it's not career enhancing for either the atco or the upset, in more ways than one, pilot.
So we check.
Even when we now see selected level from suitably equiped a/c via Mode S, if the cleared level is not given on first contact we have to ask for confirmation. You know the old one liner about "assume" I assume
