Is Hex good for Warlock?

It is relevant for assassins, for instance. The damage is nice and at higher levels the time scales up. So as a Warlock technically you could cast it, take a short rest, getting back the spell slot, and then you have Hex going. Extra dice count in a Crit, so it can be worth it for that.

Can two warlocks Hex the same target?

warlocks hex the same target, the target should suffer only one ability debuff with disadvantage, but the two different warlocks could get damage bonus.

Does a short rest interrupt concentration?

As a short rest does not require casting any spells, cause damage, inflict the incapacitated condition, kill you, or cause any environmental phenomena, it does not end concentration.

Is it worth it to use hex as a warlock?

The damage is nice and at higher levels the time scales up. So as a Warlock technically you could cast it, take a short rest, getting back the spell slot, and then you have Hex going. Extra dice count in a Crit, so it can be worth it for that. Also as said above the grappler combo is amazing.

Can we talk about that here, Warlock class?

Also as said above the grappler combo is amazing. Honestly the downside for hex is early on it eats up that slot, it really should be a class feature (This would allow players to utilize Hex “X” times per day and still do their warlock thing), or the Warlock spells should have 1 more, scaled appropriately of course.

When do you use a spell slot in Warlock?

You use a spell slot when you cast the spell. Spell might require concentration to keep it active. When you suffer damage, you have to make a constitution saving throw to maintain concentration, if you fail the spell ends. Spell lasts as long as you maintain concentration and up to the time specified in its description.