You can get blank Mega eGo cartos too. I bought a 5 pk for about 13.50. Figured that's not too much to give it a try. As for performance, I think they produce more vapor than the std atty & cart, the carto doesn't get as hot and the vapor is a little cooler as well. No need to mess with the cone (as previously mentioned). Pretty easy to fill one you get the hang of it...get a 17g syringe for it too. I put about 1ml in at each filling. That usually lasts awhile (several hrs), depending how often I vape. If I'm at home on the puter, I'll vape more than if I'm working around the house. I had one go bad on me the next day, but another is still crankin'. I've only used 2 so far.
Overall, good bang for the buck!