They will fit your ego. They come with a drip tip, and so it is easy to just pull the tip off & refill with drops. The first time you fill, it may take a while to get the juice absorbed into the filler. I have not ever had one go dry. When I am sitting around, I just put 5 or 6 drops in every so often, and they keep vaping nicely when I am moving around. I have had a bunch of cartos, and these are the BEST, by far, that I have ever used. I have been using the same one for two weeks without it getting gunky. That's another thing I like about Halo; it doesn't gunk up cartos like some other vendors do.
Keep at it jwv, it does take awhile to find out what works for you, and everyone is different. Don't beat up on yourself for buying a pack; pat yourself on the back for how many cigs you haven't smoked!