If you are looking for a good quality eventing vest...please look for one that is not only certified, but approved as well.
Now, the choice is yours. I have friends who wear that vest, but I personally wouldn't, because it does not pass the safety standards of ASTM and does not even meet BETA Level 3 standards of approval.
If you want a vest that will do its job - look at the Charles Owen or the Rodney Powell, or even the Flex Rider. I have the Intec Flex Rider, and I like it - it does its job, and to be honest, I don't even know it is on. It is certified and approved and has passed the tests to ensure that it will protect you when needed.
Now, the vest that is becoming all the rage, for riders who are Prelim and Bigger...is the Inflatable Vest. I saw many Eventers wearing it this season, it has become all the rage.....
You wear that ontop of your regular vest, so you could go with that Intec and add the inflatable vest ontop to give you that added extra protection when needed. But I think this is more-so for Mid to Upper Level Eventers.
When looking for a vest, I suggest going for one that has the stamp of approval on it, and the ads must say "Ceritified through ASTM" and "Meets BETA Level 3" standards of safety approval.
But again, the choice is yours. Your body, your money, your decision. I have friends who have that vest you posted and are perfectly content with what they have.