I'm using the PowerSupport antiglare on my rMini. Have used it on the previous mini as well as the iPad 3, iPhone 4 and 5S. You sacrifice a little bit of clarity but I get used to it fairly quickly. The advantage for me apart from screen protection (which I find less of a issue with an iPad than an iPhone) is that it makes it easier to read and use outside and under certain indoors lighting.
Does anyone have any particularly positive experiences with any brands? Also, are the size and cutouts exactly the same across the non-retina/retina models?