two days? two days and you say nercothread? No, just no. EDIT: one day. realized the OP was old, but it was necroed two pages back, so who cares.
You fail to take into account accuracy. On paper the PDW might have a very high TTK. In reality though, the PDW has much higher accuracy than the VX6-7. It's lower RPM, it has half the CoF bloom per shot. What this equates to is the ability to consistently head shot a target is invaluable. To consistently head shot a target you need a really tight CoF. The PDW has one. The VX6-7 only has an okay CoF. Furthermore, when pushing out to longer ranges, you can still use the PDW to hip fire at opponents at maximum RPM at ranges where you'd have to ADS with the VX6-7.
