Just to stay true to expectations:
This is called a Gran Passo in Bolognese fencing.
I just don't get the "switch" part (a question of nomenclature, basically). As you are essentially making a long passing step, you're switching the leading foot there also, don't you?
In Bolognese fencing, we have the "cambiare di piede", where one foot is retracted besides the other and then the other is brought forward, so there's a real "switch" of the feet in place (more or less). Something similar is used in your Slipcut.
I think it is best described as a hybrid between the Gran Passo and the Cambiare di Piede. A passing step is made, but the front foot recedes, but only enough to place the weight of the body quickly over or past the leading foot. So unlike the Cambiare, it does not recede all the way back to meet the trailing foot.
I have not used the full foot switch as you describe, so I cannot compare. But in my practical development, I have found that attacking off a Switch-step is faster than attacking off a passing step. It may be dependent on your stance, however. If your stance is very narrow, the results could be different. What do you think?
This may be due to my personal training, but in my mind the action has more in common with the flunge, as the body weight is thrown forward and power is generated from both legs while placed relatively close to eachother.