Hi, I recently bought the EOS 7D and it has firmware version 1.07. Does someone know the most important improvements up to version 1.2.1? Is it worth the trouble updating? Is there a "fix" history to be found somewhere?
Thanks in advance.

Check this...

Canon EOS 7D Firmware Update (http://web.canon.jp/imaging/eosd/firm-e/eos7d/firmware.html)

Thank you, but I read that already. The link only specifies the latest changes unique for varsion 1.2.1.
Or is this a comprehensive list of ALL improvements since 1.0.0? Three items seems somewhat meagre?

IMHO, coming from the IT industry -- not everything is documented in release notes. Just because you don't see something listed as being fixed or improved in a release note doesn't mean some obscure bug wasn't fixed or affected.

Updating firmware really isn't a hassle, download it, toss it on a card and boot. 5, 10 minutes tops?