I feel like it would be a lot more useful if it were like the gunners deploy with headshot protection. The other stats could be toned down a bit to make room for it for balance reasons.
The Tanks deploy is a little... useless to me honestly, I almost never use it since of the aforementioned lack of head shield. All I ever use it for is a quick heal after a fight or for the rare steel peel ambush.
Yeah i never used it either, i did at the begin but it's mostly just waiting on an airstrike or headshot, or a gunner to notice you and decimate you in under a second.
The Tanks deploy is powerful when used in the right situation. ...It's #1 use is when no heroes are around, and you're soloing a huge Jack-bot. The #2 use is when running away from combat (using your boost skill), and hiding around a corner to heal much-much faster, just deploy yourself and then un-deply and you'll be healed and can run back into battle. #3 is to solo enemy towers: just throw your Blinding Grenade on an enemy tower (to disable it for a while), and then sprint up to it with your boost skill, and deploy and destroy with your Jet gun! Don't forget that you get infinite ammo when deploy is lvl 3. ...It's much less useful on some maps, and against certian enemies (snipers, gunners).
A juiced, deployed Tank will absolutely decimate the enemy moneyball. It's really the only time I ever use the Tank's deploy, though.
The Tank's deploy is used for slow moving or stationary targets, so the Jackbot, turrets, and the Moneyball. It makes him one of the best at taking those out, with the exception of the Assassin's and Sniper's grapple. The product grenade is even designed to stun turrets just long enough for you to jump in and deploy in front of it before it can start firing on you, by which point you'll always win unless it's upgraded/hacked, and you're at level 1.
I use deploy in a much more dynamic way during combat because when it's upgraded you get a lot of health back.