I like to have them and use them. I do remove the optic so I can use the BUIS. I like the Matech I have you can buy them used for under $50 and use the standard front sight. I also have KAC and Troy but I promise I’ll sell the Troy. Also I’ll sell anything smith and Wesson, colt and HK but...
Yes he is expensive. Arfcom says these are stolen, people question whether legit or stolen or even real. A legit business is selling them on their site so I doubt they are stolen. Also I think eBay would be shutting down the sale of these as well if they were stolen.
This is not the source the op was referring to. The op was talking about the ones on eBay for $60. Charlies customs sells the USMC marked sights for double the price. In other words buyer be aware for the eBay items.
Buy both if you don’t mind having 2 striker fired 9mm. I own the HK but have shot both firearms and like them both. I like the HK mag release but I don’t mind the traditional mag release either.
So if you can afford both then buy both.