From a 30d to 7D or 5DII?

I love both cameras, but the 7D is more of a pro body in every way over the 5DII, save for the sensor. It is a complex, very capable piece of equipment that reminds you every day that it's not to be handled like a $1500 point-and-shoot.

The 7D feels better in your hands (especially with the BG-E7 IMO.) It's VERY rugged, weather-sealed and just feels more solid in general than any other camera in it's class.

The 7D focuses faster, tracks action better, shoots incredibly fast and furious (27-shot, 18Mp bursts @ 8fps!!!) The IQ is amazing when you learn how to dial it in, although the 5DII edges it out there, particularly above ISO 1600 (but the 7D is more than capable above 1600.) Look at the recent ISO 12,800 post in this forum.

The small pixel pitch will mean you have a steep learning curve. All those habits of proper shutter speed go out the window, and you'll need to learn how to use back-button focusing.

It's all worth it. I was just starting to love my 7D these last few months after 2 years of not quite being there (me, not the camera,) and then they turbo-charged it for free this week ...amazing!

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-Joe