I have both the Ithaka and the Kayfun (Lite and 3.1). The Kayfun is an easy build, and for me, more suitable to an ADV. The Ithaka is not much harder, and also provides an incredible vape. I use my Ithaka on oua Just GG and my Kayfun in hybrid mode on a Semovar. I would not pick one over the other, and enjoy them both equally well. They are both top of the line excellent craftsmanship. If you are new to rebuilding, then the Kayfun would be the way to go. If you are more advanced, you can do a lot with the Ithaka. Be careful, though, once you get to this level, you may never go back. Best vape in the world I have gotten from these two devices. I have to lower my nic about 6 mg/ml to vape in either device, or the hit is a bit too much for me. By the way, the Kayfun Mini 2.1 can also be used as a dripper and is also very nice, and next on my wishlist, along with an Origen Dripper. Good luck to you. Get both, perhaps the Kayfun first. All the bes!