I don't think that anybody is saying the LN bearing is junk, but to say that any product other than the LN bearing is junk/inferior is a tad bit ignorant. If you look at vertex's ebay listing, you'll notice that 42 have been sold.
Porsche IMS Intermediate Shaft Bearing Repair Eternal Fix Retrofit w Oil Feed | eBay
Now I know that's not a lot, but given that there are probably plenty that have been sold through their actual website and other retailers we can conservatively estimate that there have been at least a few hundred installed over the years. Out of everyone who has installed one, I don't think I've ever read about a single failure. Am I saying it's better than the LN? I don't know and I really don't care. But is it fair to say that it's a bad product? Absolutely not.
Again, I'd like to make it clear that I have no horse in this race. All I'm trying to do is provide some objective information on the matter.