I'm considering upgrading my long lens to a new 70-200. My two best options at the moment are the Sigma 2.8 APO EX DG OS HS and the Tamron SP AF f/2.8 Di LD (IF) Macro. These match my criteria of being long enough and fast enough for portrait work to action shots. I already have the 10-70 range covered with a couple other pieces of glass and can't really see a need to go longer than 200. The K5 has an APS-C chip anyway so it's an effective range of 320 or thereabouts.
Does anyone have any experience of either or both of these?
Also, I note the Sigma has inbuilt image stabilisation which the Tamron does not. My K5 already has on board shake reduction (which gives me satisfactory results) and I understand that one does not use both body and lens stabilisation simultaneously.
Any thoughts on the Sigma OS stabilisation being superior/inferior to the K5 on board stabilisation?
Any other comparative thoughts between the two?
The Sigma is about AUD$450 more than the Tamron so is it $450 optically better, or is that just the price of in-lens stabilisation.
Any comments appreciated.