By coincidence, I've just come in from the shed after testing nailer/staplers for putting 7mm veneered ply onto some oak shelves I've made for the eldest daughter. I knew I had one somewhere, I found two, one an arrow that fires just brads, and the other a tacwise that fires both brads and staples. I seem to remember buying one for a job years ago and getting another in a job lot of tools I bought
The tacwise is easier to load and seems to have a bit better penetration, both struggled firing 25mm through the ply and into solid oak, but the tacwise was in that bit further and on the 20mm brads and staples its just about flush. Both went through softwood with ease though.
i used it to nail some shiplap where i had limited access down the side of a building so couldn't swing a hammer, worked ok from memory, it was a few years ago.....