I have a matrix reborn and i although i am very satisfied with it i want to try something more powerfull so i decided to buy a dragon cam. But the store i am buying my stuff has only the T-Rex module. I was told that T-Rex is an immitation of Dragon 4.01. Are there any differences between them and if yes which is the best? Will my Cas3 recognise the T-Rex or should i look somewhere else to find the Dragon cam and buy that one???