I’ve been gravitating more and more towards bigger light sources lately and, at the time of writing, this is the biggest and softest modifier I own. This is not the cheapest octabox of this size but I’ve taken a liking to the Lastolite brand and their quality. Not only does it fold down and pack quite small (relatively speaking), it also feels like it should hold up well to most abuse you’re likely to put it through.
I typically use this octabox with two hotshoe flashes in it but you can also get adapter rings that makes it compatible with most bigger lights as well, which makes it more versatile if you upgrade your lights at some point.
Since I got it, it has become one of my favourite modifiers and it’s usually the first one I reach for when shooting portraits.