I picked up the Maybelline Baby Skin Instant Pore Eraser last week with high hopes as I've seen this product raved about from many bloggers for some time now.
This did nothing to blur my pores as you can see in the photos below but that doesn't mean it wasn't a good primer. In the before photo you can see some oily areas between my eyebrows and in the after one my skins texture is much more matte.
As for the primer aspect it worked okay, it didn't wow me but it wasn't completely horrible. When you apply it although you can't see it there is a greasy film left on the skin and it doesn't sink in it just sits on top. You go to scratch your face or something and it feels like you rubbed your ginger through oil it's not a pleasant feeling. Once you add a layer of foundation on top though the greasiness I mentioned above disappeared so I'm not sure why but this is definitely not a primer I'd wear alone.
Even for a primer it didn't keep my makeup in place any longer than anything else I've tried and by the end of the day there was some patchiness where my foundation had broken up. I wouldn't buy it again although Maybelline is one of my favorite drug store brands.
I do think it should be rebranded as just a primer because for me it did nothing in the pore department which is what it's marketed to do.