I have one of the PTI coverplates and use it in my Big Kick. At first I put it through the Big Kick straight-on, with a full straight edge going through first; this resulted in a great deal of stress on the machine and me. I learned to put the die into the machine a little cockeyed so that a corner would go through and the area being cut would gradually get larger. Because it's such a large cutting area, there are bound to be weak spots; I merely added a Post-It scrap to the parts that didn't cut through immediately. Also remember to rub the die with wax paper or dust it with an Embossing Buddy or add a piece of wax paper between the die and the cardstock or paper you are cutting; these will help the die-cut release from the die.
I don't consider my adaptations to cutting with the coverplate to be problems or reasons not to buy one. The die itself cuts very well, over and over and over; I just found ways to make the process work better for me.
I have not had any problems ordering from PTI, although others did for a while. I hope for their sake and ours that the problems have been solved.