Did any wrap-style neck pillow actually let you sleep on a plane, or is it all placebo? Pillow

Aisle seat is the real problem and no pillow fixes it. There is nothing to lean against, so anything that supports your head has to hold it upright rather than catch it, and that is much harder. Two of my six annual flights I now book a window specifically to sleep, and it has been worth more than every pillow I have bought.

The wrap style works for exactly one failure mode: head falling sideways. If your head falls forward, which is what you described, the internal brace has to be positioned under your jaw and slightly forward, not at the side, and almost everyone wears it wrong on the first three flights. It is not placebo, it is fiddly. Practise it on a sofa before you get on a plane, which sounds ridiculous and is the difference between it working and not.

Packability answer, since that is your actual constraint: the wrap styles compress into a small pouch that clips on, which the horseshoes do not. If you are choosing between two things that both half-work, choose the one that does not eat your bag.

I own four neck pillows and regret three. The one I kept is a plain memory foam horseshoe that I wear backwards, with the thick part under my chin, which stops the forward nod and cost about a fifth of the fancy ones. I only discovered this by accident on a delayed flight and it has been my whole system since.