Where did you get yours at? Who is the manufacturer? I don't think ANY security pouch is completely comfy, but I really don't like the waist pouch and wouldn't wear one around the neck as it's visible.
we borrowed ours but you can get them at any luggage store/walmart/etc. it had a rope and was similar to wearing a purse across one shoulder to the opposite waist. ours wasn't those exact ones but almost identical. i think i found it on the website you found your security pouch.
it fit under our clothes without an issue. and there is a wire in the strap that won't allow it to be cut with a knife/box cutter/whatever else anyone can come up with.