I have and like my Hitachi 18 gauge nailer. Often use it on projects to hold things in place until I can get a few screws in place. For this purpose I often use the 2.5 inch nails, the maximum size. It also uses easy to get Porter Cable nails.
I have an off-brand 23 gauge pin nailer that is useful for holding things in alignment during glue up. I think with really short pins you could use it for miniatrues, but it will not hold things together. A light pull or twist will pull the pieces apart.
The more I do, the less I accomplish.