To the best of my knowledge, the difference is the engraving. Also, project sub ohm products get released slightly before the regular edition. I believe that the theory is that project sub ohm has a following and that the release will hype up the regular release.
They make it seem that project Sub ohm is inputting original ideas into new versions, but whether these upgrades are a product of project sub ohm or just a logical progression in upgrading of the device,I do not know. But generally, an exact release of the project sub ohm release is released under the original name under a v2 edition.
So it may be the original manufacturer releasing the next release under the sub ohm name for hype, or that sub ohm inputs a change in exchange for an early release of the product.
