I had bought some cheaper ones, but I decided to buy this one after doing some research. It last a lot, and you can fully charge at least a couple of smartphones. It's bigger than other models, but it lasts for longer. So for a woman that usually have a bag, it shouldn't be a problem.
I've been using cheaper ones from Sainsbury's and Boots until I used this ones one day because there were no stock for the cheaper ones. They are awesome! They feel so good and you can use them for hours when you sleep but they don't move so you won't soil your clothes. Also, in summer they don't stick to your body. I love them and I wish I had discover them before!