We used the crib tent with Dylan. It worked well for a while, but my escape artist at one point pulled the whole thing down and it was upside down inside the crib! He should not have been able to do that, though, but he is unusually strong.
Eventually, he learned that if he poked his finger hard enough and long enough at the zipper from the inside, it would move just enough to sneak his finger out and unzip it himself.
It did work well for quite a while, but then we just switched him to a bed at around 2 years old.
I kept it and will definitely use it with Carter when he starts climbing, but what I didn’t like about it was we had to get it for Dylan at around 9 months old as he was throwing himself spread eagle out over the top of the crib and when I would still go in at night to check on him, the zipper made noise that would startle him. Also, if he was already asleep and we tried to sneak him in there, the zipper would sometime wake him up when we were closing the side.
OK, now I’m rambling, but bottom line, it kept him safe until he figured the rest of the stuff out and I would use it again for Carter.