Silver not much different to Bronze?

Slightly more accurater manses

Slightly more headbutts to kill

that's because you are so pro that you don't feel the difference

Outlaws are so much easier than the other factions if you mostly played them you would have a warped perception of the difficulty of silver and gold. I've never failed to extract once against Outlaws on silver and i've heard and am yet to verify that they aren't much harder on Gold.

Remnant and Kett however are different gravy though and if you aren't having any trouble carrying 2 trailing pugs (av.) on silver against those two in latter waves with shit gear then well done you, sir. Every silver game against those two by about wave 5-6 half the squad is wiped and it feels like i'm soloing gold with a Katana.

There is a definite difference between bronze and silver. Maybe I notice it more because about half of my games have been played on a Krogan engineer, and so I really notice the difference with overload. On bronze, a charged overload with no damage increasing talents (rank 3 or below) will completely strip an enemies shield. On silver, you have to take all of the damage increasing talents up to rank 6 to fully strip the shields. So considering as a engineer shield stripping is sort of "my thing," I really noticed that difference.

Mobs also definitely have more health. My infiltrator has a nice gold gun, but it's moderate damage (for an SR) with moderate clip size. Unstealthed with no damage bonus I can one shot an assembler without worrying about finding the weak point. On silver, unstealthed with no damage bonus even hitting the weak spot will only bring an assembler down to 10% hp.

There are definitely differences.