Full body swimsuits

I compete at triathlon (the modern pentathlon variety, swimming, running, shooting), which entails a 100m sprint swim in a pool. Recently many masters competitors have been sporting full body suits, and claiming that this has reduced their competitive times by up to 6 seconds over a 100m! Is there any evidence that these costumes can bring about such dramatic improvement? My own feeling is that if they do, then it's a form cheating as the costume has become an artificial aid - so I haven't invested in one yet! What is the general feeling about the use of these costumes for pool events? Joan