What do I think? You mean, aside from the fact that the name "hooter hiders" revolts me???
I don't use cover-ups for nursing except in certain rare situations like being at the beach when my whole breast really would be exposed while I pull down my swimsuit to bf my child. I find it awkward and cumbersome to use cover ups. They look more obvious than just nursing.
But if someone else wants to use them, I'm not faulting them. I think some women have been made to be so self-conscious that they are afraid not to cover up when nip. I no longer care.
I nip all the time and don't think twice about it up until age 2 or so. At that point I don't nip b/c the older kids can understand waiting and while it really wouldn't bother me, I'm actually afraid some nosey idiot is gonna called CPS or something. You never know in this society...
In deference to those who really genuinely are uncomfortable seeing moms nurse in public (regardless of how ridiculous I find that), I take care to be deft and discreet and choose the less obvious places to nurse if they are equally convenient and comfortable. I'll turn my body to the side to increase the privacy factor while I sit watching my older kids at the playground, but I won't leave the playground. I'm happy to meet people part-way and show them that I do have some respect for their "sensibilities", so long as they don't demand I stop altogether.
I like to think that by demonstrating that mamas nursing in public can be very discreet and considerate and such, that people will grow to see that nip is just no big deal. I personally couldn't care less who gets a flash of skin and no way am I being moved off to the bathroom or hidden in a dressing room (unless I go there by choice). But I never found the "in your face" approach to be productive. So my approach is just to simply, quietly, discreetly, happily, go about our business with confidence. And really, nobody seems to give me any glares or comments.