I have the DO myself. A pretty good copy of it, in fact. Not sure how it stacks up in IQ with this new 70-300 though. I'm considering making the switch if there's a reasonable difference.
I had a very good copy of the DO... I liked it a lot until I went to the 1Ds2, and there it didn't really seem to hold up.
While I haven't had a chance to compare the DO to the new lens yet, based on my comparison to the 100-400 IS, I have 100% confidence in what the results will show. --c
Could be interesting to see the DO and the new 70-300 compared. My DO is pretty sharp, but it has its weaknesses. It can be a bit "hazy" wide open with high-contrast subjects (which I experienced last night, unfortunately). It's such a handy, portable size that I like having it in the stable, even if I rarely use it.
Having previously owned the DO, while the compactness and non-rotating fron element were great, that was about it for me. I find the image qualitly and price to be much nicer on the new 70-300 IS.
