I'm thinking of selling my Canon 24-105 f/4 with IS lens. The two lenses I'm thinking of replacing it with are the Canon 24-70 f/2.8 Mark I or the Tamron f/2.8 24-70 with VC. Has anyone used and/or compared both of these lenses? I would like to hear of your experience if you have as well as your thoughts, inputs and recommendations. I would use this lens as my walk around lens, indoor functions, sunrises and sunsets on beach and video. As much as I'd like to have the Canon 24-70 MK II, it's a bit out of my budget. For portraits I'm truly enjoying my 85mm f/1.8.