i actually went out an bought the spyder 3 pro yesterday but using it on my glossy imac monitor seems to be an issue.. also luminance in the 24in imac ( 3years old) is ridiculously high.
Something is strange, what Elena and Mark wrote, and even if more polite and saying subtle magenta tint, it's an obvious magenta tint.
There's something wrong and your white balance is off. Once you get it, you'll be happy and what you see will be what you really get.
Did you set the Spider for the right kind of display? Macs are supposed to be better than PCs, out of the box.
I have the Huey pro and love it. Some people swear by it, some swear at it. Some like the Spider... I never owned one. But in the end, if you get it set right, you'll be very, very happy and looking back at your old photos, you'll be surprised to see what you couldn't see before.