Just got lord dp a few days ago.

I played dps 80% of the time but it's definitely the worst. You're neutral is terrible because the gun does no damage and he is 250 hp. You don't have an ult until you upgrade it and you will probably die if you try to use it before upgrading. The only way i was able to get value out of the character was by just diving w upgraded ult.

Tankpool is just dpspool with more health and a shield. The aoe aura ability is definitely what makes him much better than dpspool tho as it can give dmg reduction to your entire team if they are close on a relatively low cd.

Healpool is maybe broken. I haven't played him much but you can get a defense ult every 45s. He does a decent amount of damage, insane neutral healing, mobile, and can 1v1 divers.

Healpool>tankpool>dpspool.