I bought this in 2007 and waited this long to write a review since I kept thinking it wasn't as bad as it was.  The heavy metal and spring mechanisms will fight the strongest winds by giving so that it won't break.  However, if the slightest gusts hits it from below or even from straight on it'll invert easier than the $3 umbrella you can get at the Walgreens.  You have to consistently hold it into the wind to prevent it.  I live in Chicago and it's not all that windy most of the time but using this umbrella has still been a huge pain.

I wound up lending it to someone and just let them have it and am using my $3 umbrella again and hope a different company's model works out better.

Update Jan 31, 2014: I purchased the Leighton Windefyer Falcon Umbrella over a year ago and have absolutely loved it!  In fact a work colleague had another Shedrain and was disappointed with it so I recommended the Leighton and he loves it as well.