I don't have much experience with them, but I would think, in terms of use, they're the same. Quality, as in how long they'll last, might be a different story.
If you're shooting outdoors, you'll need some sort of stand...... or an assistant.
True, but they don't all reflect the same. Just because two reflectors look like they have the same white surface does NOT mean that they will reflect the same. One of the things that you are paying for and getting with Lasolite, Photoflex, etc is a higher-quality, longer wearing reflective surface which will NOT reflect unwanted colour casts onto your subject. Quality is worth paying for!Reflectors reflect. Even the cheap ones.