Maybe he's referring to the separate hubcentric ring on the Ichibas? Not really a crazy weak point, more of a design choice. I much prefer bolt on spacers as well since pulling and pressing in wheel studs is burdensome. The only real thing that matters for wheel spacers is that they're flat and the bolts are strong.
Right now I have a 35mm spacer in rear without issues with an effective offset of +0 so it's way further out from the hub than most. This is an eBay bolt on spacer too so from what I've read, my wheels should have fallen off by now after my car exploded. But Jumbo is right, a spacer is a spacer. I've run dozens of spacers since starting to mod cars in the 90's and have noticed zero difference from eBay spacers to H&R, Ichiba, Autozone, even home made ones I made on a waterjet. Never had spacers cause vibrations or anything like that.