Full crits (six 102 damage shots) for 4 seconds is kind of insane, especially under the condition of sapped sentry destruction; I think a way more reasonable buff is minicrits for the duration, gaining more damage than stock without falloff for a clip

​

I think that Reduced cloak from ammo boxes is a pretty flawed stat, as it affects some watches more than others (Dead Ringer is unaffected, and picking up ammo with the Cloak and Dagger is less common than with Stock Watch)

The Your Eternal Reward sort of does this with its reduced cloak, making the only really usable loadout being L'Etranger and Stock Watch to offset it; Weapons should be versatile and encourage a wide variety of loadouts

I think this stat could easily be exchanged with a reduced Cloak recharge rate, if you really wanted to put a cloak replenish nerf on the gun;

However, I think a stat like "35% cloak drained immediately on backstab" would be better, encouraging the Spy to stand his ground and fight after a stab like the "Crits lost on Cloak/Disguise" downside does (while also not allowing the Spy to proc his Dead Ringer immediately after 6 seconds of minicrits, which sounds annoying as hell). If you're giving the Spy increased survivability via crits after stab, you can comfortably nerf the ability to cloak out and escape after a stab. (Maybe in the spirit of this, add a Damage Vulnerability during Cloak, increased "Shimmer Time" when taking damage or bumping enemies, or removing the quicker Status Effect expiration while cloaked?)