I already own a Sigma F2.8 70-200m lens, trombone type, and thinking of upgrading to a newer lens. I can't afford the equivalent Sony (here is the cheapest I've found), but am seriously considering this.
How good is this lens in comparison to the Sony?
It will be used on an A100 and/or A350.
FRIPN. Never argue with an idiot. They'll drag you down to their level, then beat you with experience.