We wear one and find it satisfactory, but we use ours only in warm/hot weather. Although the thing has an inner liner, we have never used it. We switch to a leather jacket when the temps go below 80F. Our Joe Rocket Phoenix is now three years old and is used quite a bit. It seems to be holding up well.
The jacket is reasonably priced and works well above 25C/77F. Below this I wear leather. Without the liner it flows air really well. There is reasonable forearm/elbow as well as back padding. There are adjustments for the forearm and waist. It would have been better to get a light colour. Black gets hot.
While I have not crashed tested any of my gear, I feel it protects me reasonably well, but not as well as leather. I have seen crash photos of some who have gone down and the mesh keeps the armour in place.