So OnePlus DASH is better than Qualcomm due to it maintaining a higher current so the the recharging cell inside the phone is able to take more current at its native lower voltage, so less heat in the phone so it can ingest energy faster.
Qualcomm does it in a less efficient way as it keeps the voltage higher so the phone must do a DC-DC conversion inside the phone which is never 100% efficient, so it makes heat.
Also the removal of heat via the better DASH approach means the phone also recharges relatively faster than QC when the phone is in use and the GPU and CPU are more active.
So overall in everywhere measurable way, OnePlus DASH is superior to Qualcomm Quickcharge.
When you combine the side fact that OnePlus is lower cost phone for similar specs to higher cost phones, it is why is seen as a no-brainer decision for spec, performance, and cost conscious deciders of phones.
The issue with DASH is its proprietary nature based on VOOC
And OnePlus is still relatively niche
So (the discussion point) is given Apple does not use Qualcomm so does not have Quickcharge, and Apple is moving towards USB-PD, given USB-PD allows for higher current, USB-PD can become the winner ultimately.
Qualcomm is moving to USB-PD anyway
So given USB-PD can be an underpinning of a high-ampage profile use to be nearer to DASH charging, and Qualcomm QC4 based phones will support USB-PD, and with Apple moving to USB-PD, then we will begin to see manufacturers like Anker able to shift from QC to USB-PD through 2017/8.
We can then get back to a common standard, or least a common denominator better than a 5V 2A 10W slower standard than the 20W+ we can see with USB-PD.