Can’t speak about this specific model but they are all fairly much the same, I guess.
Portable, yes, but a bit of a pain.
My one, it looked like any pressure on the bolts and they would break. So I replaced them with bigger ones.
My one, uncomfortable and when you leant back, the bar would move because you are attaching around the pivot point. I overcame this by bolting another bar from the rifle rest to the seat, made it a much more stable platform.
Not something you want to leave out for too long, keep an eye out for rust on it.
My one, It is portable and flawed. It can do a job. But, I would be looking at other options now, if I was spending money.