This is not the case for me. I just looked at hole placement in my heads that are vaping great and the slight difference in hole placement has made no difference to the vape quality in either taste or vapor production. I'm just not noticing a difference at all in any way. All the holes shown in the picture are going into the same loose polyfill at the bottom of the tank, and you can see the white polyfil through the holes, so I don't see why such a small difference would make such a dramatic change in your vaping experience. As long as the holes allow juice to migrate into the polyfil, the entire poyfil matting should saturate just fine. If there is a difference in vape quality, I think it must be something else based on my experience.
Now if the sheet polyfil isn't pushed far enough down to make good contact with the loose polyfil at the bottom of the head, that would certainly make a big difference and I've been wondering if that might be the case in some heads. I know a few have issues with these heads and if it doesn't wick correctly to the coil I could see this as a potential problem. Since I haven't gotten a bad head yet I don't have any heads to check this on, but I would be interested if someone with a bad head could check this. This would seem a much more likely reason to me.
The other thing to check for is if the coil is centered properly. If the coil is touching the polyfil sheeting on one side perhaps it could cause burning of the sheeting giving a burned taste. I haven't encountered that, but if someone has a bad head please check that also.
Not sure what the issue is for some, but hole placement doesn't affect the vape for me at all. YMMV
