I've decided to leave the attys in the box and use cartos. The 306 on my Blu and 902 is pretty awesome... the taste and vaper is so much better than with an atty....What other cartos can I use? Can I use a mega 510 on a blu or 902? Any recommendations are greatly appreciated? Are other cartos as good as the 306? (a carto is a carto or some have it and some don't) I'm going to be making a madvapes purchase and would like to throw some more in the box, but they don't have 306 cartos.