I believe that the main reasons for diverting the world to helicopters from autogyros was that there are problems making gyro a) big and b) with enclosed cockpit. Since most of aviation development and progress is practically paid for by govermnments and military - they simply didn't need these little whirling things which cannot carry even one plutong nor Sherman tank.
Thus gyro - thanks to Bensen - has found it's place at least in recreation. I believe it will find it's place in some aerial applications too - next decade. Actually some problems of light gyro were solved last few years only and some are to be solved yet.
As for our experience, there are real advantages in gyros for at least some aerial applications such as traffic control or carrying cameramen.
We flew our Dominators with videooperator aboard for some car rallies, ski races, yachting races etc. As I mentioned above, videomen were really excited with visibility and low vibrations. Once we flew it in 15 through 18 m/sec (yes!) wind (and it was winter, -15 C OAT. The gyro lets show it's possibilities in such wind even better than in no wind condition: it can even hover. And it has no tail-wind fear like helos have.
Another special thing is that it is easy to drive autogyro at low (and very low) AGLs having different speeds - which is dangerous for both any helo and fixed wing.
Just my 2c.
Cheers,
Alex
http://twistairclub.narod.ru - Rotorcraft in Russia