I just got an HCigar Akso (won from HeavenGifts). I haven't tried the IJoy AI, but have tried Juul, Infinix, Vaporesso Zero, Innokin EQ.
Very similar to Juul in size & shape, but I like the design a little better.
Very responsive draw activator compared to the Zero, which you had to draw hard and quick on. EQ delivers a better hit than Zero, but isn't draw activated.
This thing delivers a serious hit, and more vapor than any of the above. And the flavor really comes thru much stronger than any of the others. But it comes with 50mg nic salt juice, and I can tell it's most, if not all PG. I can't really vape pg.
On the bright side, you can buy empty pods and fill with your own juice. I really like this device, so I'm considering trying them with my juice. Downside is the empty pods are about $4-5 each, but being ceramic coils, they should last pretty well. The empty pods you buy are a little different than the pre-filled. You can't refill those, at least without doing some hack to get them apart.
So far, this is my favorite pod, if the replaceables last or get lower in cost, and perform like the pre-filled. But right now, it's not real easy to find.