I was just wondering if anyone has had experience with the Sigma 70-200mm f2.8 EX DG APO Macro HSM II (phew!) zoom lens? I am considering it as an alternative to the Oly 50-200. The Sigma has the advantage of internal focusing and zooming. My experience with Sigma lenses has generally been good. I see they have just released an OS version of this lens but that variant doesn't seem to be available in Four Thirds mount, not that that is likely to be an issue with anybody except E-1 users.