I've purchased a K1 and I'm very happy with it. A few days later I ordered a pack of BVCs via Amazon. Unfortunately the supplier, a austrian company, placed a Barcode label over the Aspire Scratch label, so I was not able to verify if they are authentic. Packaging and everything else looks ok.
Now I replaced the included coil from the K1 and noticed a slight difference, the air holes from the included coils a much bigger than the ones from the replaced coils. Everything else looks the same. Both are specified with 1.8 Ohm and 4.2 to 5.0V
Have you changed the size of the holes over time?