I've got not much to add, because I have boge's, and I usually drill the 2 holes that it comes with bigger (because I often use thicker juices at much higher power, and the absorption rate out of teeny holes weren't keeping up).
I have around 30 carto heads to use up before I need to order more, but the time saver of not having to expand the holes myself makes Ikenvapes really appealing... but I'm going to use up my cartos I have before ordering any.
The boges work great, but they are flangeless. You can get them almost anywhere too, just look for punched ones. I only paid $6 for a simple punch. All it is is a round piece of metal with a screw hole. You push the carto in and then tighten the screw and it expands the hole. They are very simple things that if you have any tools laying around, you can probably make one yourself. If you use relatively thin juices that aren't sticky types, you won't need a hole punch.
