I have been doing this for nearly two years now as part our security training at my job (not specifically through them but they do offer many courses).
It's very easy to use once you get used it - however that can be difficult when learning how everything works! They also give plenty if support so even after we've left there are still people who will help with any issues/questions from time too far removed away :) Our employees train daily using these sessions which is an added bonus compared previous times where only some would occasionally come across something new while other were more likely not trained enough yet etc..