Using an Aspire BDC on either my VTR or 134 I can vape up to and above 12 watts without getting that burned taste. Not exactly sure what the difference is, but compared to my Vamo V3, Innokin SVD, and LVT these two seem to provide a much smoother cleaner vape. The VTR goes to 15 watts. I didn't think I would ever like a box mod, but the VTR is a killer I love it.
The difference is that BDC (Bottom Dual Coils) run at roughly twice the power of single coils.