In any event, I finally procured a battery pack for this tool, and used it today for the first time. It was rather impressive and fun to use, and certainly convenient. As suspected, it's quite easy to overapply the product, but there's a handy output regulator to help properly meter the product, and with only a couple feet worth of practice, it was a cinch to use.
I used it to apply beads of 3M 101 polysulfide, which is generally fairly easy flowing. I'll be interested to see how the tool handles the incredibly stiff 5200, but I don't have a need for that in the foreseeable future.
The caulking gun is huge, but ergonomic. And the product flow stops instantly when the trigger is released. In any case, I liked it, and it sure is easier on the hands!
