I'm nearly always into emulating rather than improving the quality of a recipe first (so I know where you're coming from), in many ways so I understand how it's working at all in the first place in order to improve if need be...It's the stabbing in the dark frustrates me.
You may remember my frustrating lamb doner leg recipe hunt.
Don't CARE if you can improve the quality. I want to know how to emulate
Cheap pork sausages are a very good example of this because generaly they do taste very nice and yet are complete junk by almost anyones standards.
They're juicy and meaty and have a texture seemingly difficult to obtain in a home made recipe.
From my (admittedly limited) experiences, bread/rusk based fillers seem to do little other than soften the mix and prevent a dry dull sausage and carry some fat and flavour with it...But they still don't bring about that almost glutinous meaty sausage texture you can find in the next to nothing English pork sausages.
Apart from unknown chemicals and no doubt levels of fat way above the 30 percent I use, I do kind of wonder if they aren't adding a fairly high percentage of connective tissue (meat from pork jowls, feet, etc) to help get things really geling together at no extra cost to them.
It's not a thought many like, but cheaper bony/cartilage filled cuts do carry tremendous flavour and I do seem to recall seeing some commercial recipes pasted up on this forum that list various parts of the pig to be used that most of us wouldn't want to use and can't get even if we did.
As for me, I'm fairly happy with my spice mixture for my generic bowyers sausages (you're welcome to it if you want it - it's nothing inspired...just my own levels of spices most use) and the taste isn't too far astray, but the missing quality is the texture every time.
That said I also don't ever have to pause mid sausage with ones from my recipe because I've bitten into a chunk of something unidentifiable that's as hard as a rock, and indeed possibly actually a rock.
Rob.