Sorry to bump this nearly two year old thread, but I do happen to have the same question.

did have a look at Marhaba website and they offer a bronze and a silver "meet & greet" service, and only the silver level mentions that they'll take me through 'expedited lines at immigration.' However, one user on the LX-forum mentioned that fast track is part of the standard package too!? Don't want to go for the more expensive service if not necessary. Is the main difference just being met at the airbridge vs. having to walk to the arrival desk before immigration?