The holes in the bricks are actually a cost cutting measure from the manufactures. It removed 1/4 the cost of the brick material (but the new brick molds cost $35K - $60K each!)
I’m a fan of either - I like the version with holes (the majority of the bricks on the market) as they are lighter and seem to have less breakage on the pallet. But the solid version is more aesthetically pleasing on the base as there are no visible holes on each corner.
FREE TIP - If you want to fill the holes on the corners, simply press a handful of regular mortar into each brick hole. Push it back about 1/2" from the front of each hole. Allow the mortar to dry for about 6 hrs or until it’s firm. After that, grab a few of the edge bricks and cut them w/ a mortar blade. Collect that brick dust and add about 1:7 Portland Cement to the dust, a bit of water and mix into a paste. Then, you simply press that brick dust / Portland blend into the 1/2" deep brick hole and smooth / texture. Once that mix drys, it will be a rock-hard patch that is a very close match to the existing brick color.