Stats:
You only have 1 sapper at a time.
You can place it on a building without activating it
Right click to activate the sapping process (edit: remotely) (edit: and alert the Engineer)
+20% faster sap speed
Right click again to recall the sapper back to your hand which stops the sapping. It also returns automatically if the building gets destroyed.

edit: Maybe it should also be louder like in op's post.

Engineers are not notified of their buildings being sapped
Can only sap one building at a time

*No HUD indication, no "Spy sappin' mah" voice lines, building doesn't show as being damaged until it is destroyed
*Teleporters are the only exception, since you sap both ends. Or maybe it could be a feature that it only saps one end.

when equipped
anything you say will be sent to the enemy team

Idea: does not destroy or damage the construction, it only returns it to level 2 and then paralyzes it. Removing it costs 6 more hits from the engineer's key.

Here's an idea, a support sapper.

+ Does not alert the Engineer when placed.

+ Players on your team will be shown an outline of the building's location for as long as The Recaller is attached, outline remains 10 seconds after it is removed.

+ Dial Tone: After The Recaller is removed, the building will shut down for 3 seconds to reboot.

- Does not damage or disable buildings on placement.

- Only 3 Recallers can be deployed at a time by its owner. Placing a fourth destroys the earliest Recaller without activating the Dial Tone ability.



The idea is to give the engineer a dilemma, does he keep the "HELLO. PLEASE DESTROY ME." outline on his buildings, or risk vulnerability and remove them?

It also relies on actual team play and communication, because you can't rely on your sapper to hold a sentry down continuously while you destroy it. Also thanks to the damage penalty on many revolvers, it's really only good when paired with the stock revolver.

If you can destroy the sentry fast enough that is. You really gotta time it.

+ Saps Buildings +10% faster.

o Sapped buildings play a loud ringing sound that all players can hear.

- Plays a special ringing sound for the engineer when initially sapped. (along with the call-out)

- Cannot destroy buildings, leaving them on minimum health. (still disables them)

Allows you to hopefully play some interesting mindgames with engies, where he can't be sure if your actually going to destroy his buildings or not.

Originally posted by Perri, King of Earth:

Engineers are not notified of their buildings being sapped
Can only sap one building at a time

*No HUD indication, no "Spy sappin' mah" voice lines, building doesn't show as being damaged until it is destroyed
*Teleporters are the only exception, since you sap both ends. Or maybe it could be a feature that it only saps one end.

I love this, but only if the sapper "charges" and detonates when the sapper is hit or when it would destroy a full health building as opposed to it draining health like a normal sapper would. this would be more clear if a second class like heavy is shooting the sentry as well due to higher level players letting sentries soak up damage. maybe the ringer gets louder as it charges?

+ additional 2 hits needed to remove/double the health (4 hits on normal wrenches/powerjack, 5 for jag/neon)
+ removes ammo/stored metal while sapping sentries/dispensers
+ when removed does a small amount of knockback/jostling to any nearby enemies (if tele sapped, this applies to both teles)
+ (mvm only) does an AoE sap/slow on enemy robots

~ no random crits

- sapper is quite loud, not ear deafening loud but certainly more noticable a la Dead ringer to normal cloaks
- only 'one' sapper; used up when sapping, regained by either sucessfully sapping a building or going to a supply cabinet
- makes a slight "ring-ring" noise when pulled out, and on occasion when still out (similar to the Wheatly voicelines). this does NOT occur when cloaked.

+Disables and saps buildings once the Spy decloaks or undisguised
-It will not automatically disable and sap the buildings once they are placed.

Stats:

Pros:
- Outlines sapped building for all teammates

Cons:
- Makes a loud ringing sound
- 10% damage penalty

Originally posted by Jouppi:

Stats:
You only have 1 sapper at a time.
You can place it on a building without activating it
Right click to activate the sapping process (edit: remotely) (edit: and alert the Engineer)
+20% faster sap speed
Right click again to recall the sapper back to your hand which stops the sapping. It also returns automatically if the building gets destroyed.

edit: Maybe it should also be louder like in op's post.

sapper recharge meter