The reason you mavinim give accolades to Schwartz matyas herring is because you’ve never had the real deal. Actually, these kosher herrings are just ok but you can do much better yourself. The repackers just take herring that’s been processed and add a little oil and onions and charge whatever you suckers will pay.
The same for shtiglitz (which is a made up word), and you can hardly find the micro bits of herring in the sauce.
For fresh, cheap, delicious shtiglitz: buy some pickled herring (in wine sauce) in a jar, add some of the liquid from the jar to mayo and mix to a thick consistency, add a minced Bermuda onion and some sugar to taste, add the drained herring pieces, put in fridge overnight and you’ve got a delight you can’t buy anywhere.
The color of matyas herring should be naturally dark rusty looking from the spices in the brine, not reddish from beet juice used by the imposters who label any herring with beet juice as matyas, and you guys fall for it.
You can find minimally processed matyas and experiment on your own.
Enjoy!