Unless you are using a Dripping Atty with a side air hole or a Genesis style tank with a side air hole, you may not be making equal comparisons.
Not all Mods are going to be regulated the same, though I believe both the SID and MVP use standard 33mhz chipsets.
Simple differences in the way a passthrough tank sit on a particular Mod will effect the overall Vape experience.
Protank is a good example as it will not work well at all on a Provari. The tank screws down to far and stops air flow.