I saw the 5170G for the first time in 2013 at the Patek show in Munich on the wrist of my dinner table neighbour. Fortunately, I had the chance to try it on and immediately fell in love. It took me one year until I could call this watch my own and ever since I have never regretted the purchase despite a lot of bashing from fellow collectors.
A comparison with the 5070 is difficult or even impossible imho as these models are chronographs with completely different concepts.