+1 relic weakest upgrade for tanks?

[Maelwys]

I went for +1 first point as paladin . never looked back, never will look back, its superb upgrade and remember kids: faster dps can nuke, faster mobs die outta your arses, but for dps to nuke faster you need to be able to hold all the aggro

It pretty much comes down to "Go for the +1 weapon whenever you are having trouble holding aggro with your DPS going flat out."
For most of us, it appears that this only really starts happening at Coil Turn 2s and 4.

It's a balancing act though. You can push the Threat output up much further if you're willing to start sacrificing a little Vit and Parry for it (and in extreme cases, respecing for +Str over +Vit)

The Gryphonskin setup I mentioned above is probably the best means I've found to boost a Paladin's threat output up as high as possible whilst sacrificing as little Vit and Parry as possible. There's actually another Gryphonskin setup which pushes up a Paladin's STR and DEX as high as possible (NOT threat output, just the raw STR and DEX values) whilst sacrificing as little Vit and Parry as possible and not burning a respec: this is the "Maximum Block/Parry" configuration... which is a rather odd build but can technically withstand a higher amount of incoming damage over time than a "Full Vit" setup. (Exactly how much extra mitigation over time it provides is up for debate - the affect of +Str on Block Strength is known, but there's a lot of ongoing theorycrafting about exactly how +Dex affects Block/Parry rate...)

Compared to the Post-T5 +Vit BIS build above, you'd basically use the Valor Hands and swap all the accessories out, sacrificing 9 Parry, 25 Vit and 2 Acc for 45 Dex, 45 Str, 31 Crit, 30 Det and 7 SS.