Two things to watch out for on the istick, the metal they make the top cap where the 510 is tapped is soft, if you get an atty that starts to screw on with the least bit of resistance STOP! I took a couple threads out of the top of the 510 female threads on my istick when screwing on a plume veil even though I stopped right away it came back off hard, the metal was in the threads of the plume. I took a razor blade and got the metal out of the plume's threads then took a piece of 600 grit wet or dry sand paper and lightly polished the threads on the plume, they were very sharp and the problem is now gone. You could put a ego adapter on it or the istick bending adapter which has a spring loaded 510 and just leave it, I did that with a ego adapter for a long time but it bugged me having it on it.
The other problem I have is sometimes it doesn't fire when I push the button, I have to let off and push it again. The istick uses the button switches on the board, the button on the atty extend into the body and rest on the board switches. At some point I'll have to replace the fire switch on the board, hopefully it won't be a big deal, I hope.
There are a few youtube vids that show taking the istick apart, Busardo's vid of the 20W (below) shows the inside but there is one that's better.
https://www.youtube.com/watch?v=_W1G7p_fCJw