We've always used this type of bearing for all our builds, it has been the go to since 2012 when we noticed the vast majority of bearings utilized a "W" type Cage. The J Cage, allows for the bearings to be sheathed between 2 sheet metal plates thats crimped together.
A complex process for something so small, normally these bearngs cost a much higher premium due to the complex manufacturing process compared to the cheaper W Types.
However, this comes at a great benefit which allows the balls to be more evenly spaced under heavier loads. Most bearing failures occur due to the steel bearings bending the cage and thus causing an imbalance of weight distribution which in turn damages the ball bearing leading to failure.