Re: X-MEN: FIRST CLASS - Grading+Discussion **SPOILERS!**
In the end, Singer and Vaughn are basically saying the same thing, though it's more strongly worded in Singer's case. They're both saying that they didn't necessarily feel constrained by the prior films on a point-by-point basis. In describing that situation, it's interesting that one uses the term "prequel" and the other uses the term "reboot".
Just walk away, and there will be an end to the horror.