I can't say what is the best, but if you got 6 years out of a vest, and you were pleased with it, I would be inclined to buy the same vest again, if it is still available.
I happen to have a couple used vests for sale if you are interested. Here is a picture of one on the bulldog to the right. It is an X-Large Uglydog vest
The other vest fit on a small pit. and has some tears in the sleeves.
Let me know if you are interested in either.