Thanks to everyone who's posted thusfar. To answer some of the questions:
- Lenses: 50mm f/1.8, 15-85mm f/3.5-5.6 IS, 200mm f/2.8L, 70-300mm f/4-5.6 IS (non-L)
The 15-85 is my only EF-S lens...which also means I'd need to buy a new "general purpose" zoom if I did go full-frame.
- Budget: I don't really think about it in these terms, since I feel fortunate enough to have a job whereby I can justify spending $2,000.00 for something I'll use for the next 5+ years for a hobby. It is more an issue of opportunity cost -- if I buy the 6D + 24-105L over the 70D...it's about a thousand dollars I can't spend on other hobbies, or on tickets to the sporting events I like to photograph, or upgrading my other equipment.
Based on what I'm considering, my effective budget is less than the 5D3, but enough to justify the other options...so less than $2k.
- Can't sell the T3i, as it's going to a family member if / when I upgrade my camera body.
- Also can't see buying the 7D mark 1, since low light noise is one of my major concerns when upgrading. This is an example of a picture of mine that I love
...but for the noise I see when putting the picture on a large monitor / HDTV. (I did take this picture before buying the 200 f/2.8L...but I haven't had a chance to shoot with the new lens in that setting.)