Take a look at the reviews over at Pop Photo.
http://www.popphoto.com/cameras/4724...alpha-700.html http://www.popphoto.com/cameras/4668...n-eos-40d.html
Summary of Pop Photo reviews...
A700 is has better handling than the 40D, since the A700 now uses dedicated buttons very similar to the Nikons .
A700 has faster and more accurate AF than 40D and this is with the all lenses and not just HSM. This wa also the conclusion of the German mag Foto which also compared the Af speeds of many of the Semi-Pro cameras. The only issue with this is the enthusiastic AF motor in the A700 can strip gears in the cheaper Sigma lenses an some people have found out.
Pop Photo Page 1
"It [A700] also focuses faster than the Canon EOS 40D, Nikon D80, and Nikon D200 down to EV 4, then gives up a fraction of a second at EV 2 through -1. It's slower than the Canon at EV -2, but faster than the Nikons. And it focuses faster at all light levels than either the Pentax K10D or the Olympus Evolt E-510."
and..
http://www.popphoto.com/cameras/4911...cus-page2.html
"In our tests, the D300 focused extremely fast in bright and moderate light from EV 12 to EV 6, slightly faster than the EOS 40D,
but not as quick as the Sony A700 or Olympus E-3. In low light from EV 4 to EV 1, it was just behind the Canon but much faster than the Olympus. And in very low light from EV 0 to -2, it was faster than any other DSLR we've tested, maintaining an AF speed of under 1 second even at its limit of EV -2 (the Olympus stopped at EV -1)."
40D has slightly better High ISO performance at ISO1600 and above. Note that 40D doesn't do ISO6400, but the A700 is pretty unusable at the ISO anyway, so no big deal.
A700 has Anti Shake, 40D has Liveview.
Both cameras ave some kind of Dynamic Range technology for exposure control of difficult scenes. You already know the Sony (DRO), but it now has advanced settings which is very similar to the Canon and Nikon versions.
And my view...
I would say there are more lenses available for the 40D and are generally cheaper than the Sony lenses for the 'own brands'. Obviously 3rd party lenses are the same price, but new lenses are released for Nikon and Canon before any other brand. This could be your deciding factor as well as the cheaper price of the 40D (£150 cheaper I think)
I've read the reviews and have a good friend that has a 40D who bought at the same time that I did, hence have had the discussion about both cameras as we showed each other our new toys.
The 40D is is a great camera and I looked at the 40D when I was looking to buy my A700. The D300 was a more tempting camera but decided go with Sony. Whether I made the right choice, only time will tell.
I would say the A700 is the better camera (based on my needs), the improved handling (dedicated buttons for Exp Comp, ISO, etc) sells is for me but it is also more expensive. In fact the 40D is more like the price of the A350, which puts the Sony A350 to shame a little.
Another option is the 450D from the other discussions in this forum. But it depends on what you want from a camera. Written up your requirement yet?