What about the post snapping off above the bracket? Is this a real danger?
Not really. Anything that would snap the post off above the bracket
would snap the post off at ground level were you to just plant posts.

Or rather, the post coming loose in the bracket? It's a pinch bracket, no
holes actually get drilled in the post. It would have to squeeze the post
pretty tight to hold it in place. There is going to be a lot of pressure at

Nope. It seems like a bad connection, but as long as the collar is
deeper than it is wide, the post can't roll out of it without
breaking completely. And you shouldn't have any significant
uplift forces, (sans pig, or stubborn dog) so that fact that
the post can lift out isn't important. It's essentially
the same type of connection as the short metal tube on a
collapsable fiberglass tent-pole. It's just held in by a
rubber band, but in the direction of stress, it's stronger
than the pole.


that point, but a 4x4 is pretty strong. OTOH, there is only 4-6 inches of
post in the bracket, instead of 2+ feet of post in a hole. I have no
experience with this thing, so not sure how well it would work. Mail box,
yes, 2 foot picket fence, sure, 6 foot fence? Hmm.

Oh, and any suggestions on how to drive them into the ground and have them
end up level? It would not take much to end up with posts that lean. I'm
tempted to pick up a half dozen and see how they work. If they do, great, I
saved a lot of trouble. If they don't, I've wasted 80 bucks or so - these
things are not cheap

Start them off straight, and they should go in straight unless you hit
a pretty big rock. And you're not driving one through rock no matter
what you do.