Butterfly pills

I bought some white Butterfly pills to take raving. They have grey dots all over them, a domed bottom and the logo is sticking out (I give this detail because apparantly there is a different batch with a flat bottom and with the logo pressed down into the pill). Anyway, I've been reading reviews about them on pill reports and there appear to be two very different opinions of them. Some people are saying they are pretty good pills while others are saying that they are really rubbish and have next to no MDMA in them.
Anyone had the Butterflies that I've got, and what are they like? Because if they're shit then I'll do them all tonight and buy some different better one's for when I go raving.