I picked mine up at the PO this morning.
The first one I loaded up, works perfect, nice draw.
The second one I loaded up has a hard hard draw.
I tried them both on all 3 devices: Provari or SuperT 18 & P16 or GGTS, work the same, 1st cart great, second cart you can suck your cheeks in and still not get a decent drag!
I'm noticing that the "good" ones don't have quite as much filler, height wise.
I believe I have finally figured out why some have a hard/tight draw. The center sleeve has been squished together. I've managed to open that one up just enough to make it usuable. I've check the others (8) and found 4 more that appear to have been squished (can't see light through the center). I managed to open up 2 of those 4. I haven't given up on the other 2!
The second one is jam packed very close to the top of the cart, this has the hardest draw I have ever experienced (also had the squished center sleeve).
I should add here that I tried 2 different types of adapters 510/510 with these carts. I was thinking maybe they had a problem with airflow. This was not the case, the adapters made no difference in the draw.
I think if we could get these uniform across the board it would help quite a bit. That said, I've ordered another 25!