I "had" to say yes...
And I didn't need to think too long... only because I have allready been thinking this through for a few months now.
About three months ago I started "semi-actively" searching for a used 1D to go along with (probably NOT replace) my 10D.
The reasons I was drawn to the 1D were a few,. and all of them I truly do beleive I will benifit from.
I have grown into the usefullness of fine optics slowly,. and now I think that particular bottle neck has been remeoved from my particular chosen subject matter.. the camera itself can certainly be a benifit at this point.
As someone who enjoys primarily wildlife and bird phtography, as well as indoor theatrical events.. these are the benifits I think a 1D would give me;
1. Faster AF: With my now top of the line lenses, the 500mm prime and 70-200mm IS in particular, I think I would benifit from the 1D focus speed.
2. More precise tracking of moving objects via 45 zone AF: This would be helpfull for both birds in flight and dancers on the move.
3. Faster Burst rate: Ditto all of the above.
4. Spot Meter!!!!!!!!!!!!!!! Really helpfull in the woods. Not so important in the theatre.
5. As an owner of an f/4.5 telephoto,. the 10D will not autofics with a 1.4X T-con on that lens relaiably (I have to use tape too
) The 1D will offer AF at f/8 which will allow the full use of the 1.4X T-con,. which gives excellent image results with the 500mm
These were the main benifits that I thought could actually help me out. There are other features I really like, including the user defined shooting set -ups etc...
Anyway,. with the MkII on the horizon I am waiting,. and hoping I can swing a MkII 