I also have had the $2.89 one from amazon for a couple of months. No complaints, love it. It does muffle the speaker a TINY negligible bit, so I remove it if I'm just using my comp to play music at the moment while doing other things, for maximum quality.
Also, make sure that the cover is completely dry/no moisture at all, before closing your screen, otherwise it will leave an imprint on your screen. I've had a couple of scares, but it was easily cleaned with some eyeglass cleaner/microfiber cloth. But I've read some reviews saying that their screens were "ruined." They may have just been overdramatic. 🙄