Both are best from the viewpoint Zoro n Sanji are fighters. Oda gave em what they needed whether be this arc or for later on in the story..
If one looks at the highlights of Zoro after the ts, first thing he does is cut a ship, then then huge Octopus in the depth of Ocean and latest one in DR.
While Sanji got highligjted for his speed or more in same dealing with Octopus and in WCI arc.
Zoro might need to cut something which without Enma at his current level he wouldn't have been able to in Wano. Enma will allow to channel in all his Haki in one single strike and let Zoro perform the strongest slash he could have made. Not to mention, a better control of the Haki is also forced on with Enma, which would help his Haki control grow better.
Same for Sanji, his durability was something that was required a boost since PH and with a dope ability like Invisibility he would be able to carry out Stealth missions better. It provided him an ability he always wanted and the Speed booost which Oda also seems to be working on him post ts.
To both these characters, these PUs are good.
As a overall PU for normal people RS is better. They will be able to fly with it. Invisibility, Durability, n speed boost. While one without Haki who can't tame Enma will end up loosing his consciousness or life. Like Kinnemon mentions he wouldn't prefer Enma, same like how normal swordmen avoid Curse swords.