@Marsu42 Thanks for what you wrote. While I'm not happy it happened to other people, I'm glad I'm not alone (if that makes any sense).
In my usually doomed tries to translate German proverbs: "Shared pain is half pain" :-p ... not true, but the human psyche seems to work that way.
Polycarbonate bodies are virtually indestructible, just watch the video on DigitalRev TV where he tries to kill two cheap bodies. Their other advantage is they are light so store less potential energy, drop them and they bounce.
Interesting information, thanks - thinking back that's exactly what happened whenever I dropped my 60d (well, I try not to do it to often, but over the years ... you know :-p).
Newer mid-range alleged "metal" bodies aren't entirely mag-alloy anyway, I though it was purely marketing (esp. Nikon d7000-type, the metal is only on the top/back where the usual diagrams show it), but maybe it makes sense after all to reduce weight while having a sturdy frame against splits.
Thanks ... I pulled the plug on my plans to get the Kenko after reading the above.
I don't think it's a show-stopper, the extender is excellent and good value otherwise - but as it seems other users have also issues with the Canon extender, it seems you have to be extra-careful with these. As for the Kenko release button: Maybe you have a chance for a hands-on in a shop (or order one and then send it back for free), now you know what to look out for and figure out if it's a problem for your handling style.