Hi Brian:





Any chance you could review the Sigma<span class="text18"]APO 300-800 F5.6 EX DG HSM, or the <span class="text18"]APO 800mm f5.6 EX DG HSM? I would suspect that they are not as sharp as their Canon counterparts, but would like your view before I spend $10,000 + or so.





Thank you.