Saying the 50mm 1.8 with a 2X and the 100mm 2.8 are "pretty much the same" would be like saying that Kirstie Alley and a Playboy centerfold are "pretty much the same".
Actually Jay, you seem the understand the situation at this point, so I'll just say that you'll love the 100mm 2.8 macro. Its a sharp fun lens. Your right on the money wanting that Tokina as well.
)
