I'm going to continue on my trend of reporting things JarateKing discovers. This is already mentioned in his hud's thread but I know a lot of people haven't seen it.

Be warned: the following is an (imo major) exploit. My reasoning is that by posting it and through people abusing it maybe valve will fix it more quickly.

You can completely disable the black overlay that appears when you're scoped in as sniper with a tiny bit of hud editing. Simply copy-paste the below into HudAnimations_TF.txt in your scripts folder.

event ScopeRemoval
{
Animate HudScope Position	"9999 9999" Linear 0.0 0.0
}
Then ctrl+f for the event "DamagedPlayer" and, if it already exists, edit it so it looks like the below. If it doesn't exist just copy paste the whole thing.

event DamagedPlayer
{
RunEvent ScopeRemoval 0.0
}
It's alright if there was already stuff in the event and you can leave it if there was. This is the event that would animate your crosshair to be a different color when you hit an enemy.

Then paste the following into your autoexec:

alias remove_scope "sv_cheats 1; testhudanim scoperemoval"
remove_scope
Voíla, your sniper scope is removed and will now look like this while scoped in (not my screenshots):