My issue is that a familiar's HP never scales. Not much more than that. If they had like half the wizard's HP, or something, I'd feel better about them.
Sent from my iPhone using Tapatalk
Strictly for a PotC Lock: For all the really useful tricks, if they're taking damage, things have already gone mammaries up. Sure some extra hit points would help mitigate the odd trap or attack but hey - at least this way folks are less likely to try to throw them into combat (where, arguable, you get the least return for your investment, again with regards to PotC lock.) Use their senses, use their thumbs, and heck be sure to use their brains (A standard Owl familiar has an Int of 2. Compare it to say, a Sprite's 14? I know who'd I prefer making judgement calls while my character is asleep!).
I don't know, one of the most common uses I've seen for the Imp familiar is to have it use the Help action in combat so as to grant advantage on an attack (your own or someone elses). (Help action isn't an attack and so doesn't break invisibility). Can backfire when you run into an opponent that can target invisible creatures, but tends to be very helpful at the low to mid levels. This is in addition to the normal scouting duties and such.
One of my warlocks has named her Imp "EMI" for "Emergency Medical Imp" - he has a bandoleer with 4 healing potions and can invisibly deliver them to people (and even feed it to them) as needed.
It's also why the Owl is one of the more popular 'normal' familiars in the groups I play with - flyby lets it fly in, "Help Action" and then fly out of reach without provoking.
The thing is: Chain Warlock can give up one of his attack to let his familiar attack with its reaction. Wizards, Tome warlocks, any class that could get the Find Familiar magic can't attack with his Familiar. That's the difference between them. Since the Imp has a great poison damage, Chain Warlocks can be much more effective then wizards. And don't even forget about the Invocations Warlocks get.
Except you use the Imp's attack bonus, and Warlocks only get a single attack. Past level 5 you'll do much more damage with your own Eldritch blast.