So I found this item..

[FenrisWulf]

Ah, thank you, adeyke. As you may have noticed, I was a bit off in my calculations; I forgot to take into account the effect of the existing on-weapon ED. Whoops. :P

Setting up an inequality:
for d = +% ED already on the weapon
e = +% ED from skills, stats, other gear, et cetera
s = +% ED on the jewel/rune you're considering socketing instead of a Pul,

if s > .75 * (1 + d) / (1 + e), then the jewel/rune will be more beneficial than the Pul.

What this shows is that if you have a large amount of external +% ED, or a small amount of on-weapon +% ED, the jewel/rune will become increasingly effective in comparison to the Pul. On the other hand, a very high on-weapon +% ED or fairly low external +% ED will make the Pul look more attractive (against Demons, of course).

In this particular case (+588% external ED, +234% weapon ED), a 37% ED jewel will be more effective than a Pul against Demons.

For a Perfect Tombreaver (+588% external ED, +280% weapon ED), you would need a 42% ED jewel to work as well against Demons as a Pul. :P (of course, an Ohm would be more than equivalent)

And, if you chose to hire a nice Might Merc (assume slvl 15 Might, taking you to +768% external ED, +280% weapon ED), then you're down to a 32% ED jewel.

With a slvl 25 Fury (adding 102% more external ED), on top of the last situation, we're now down to around a 30% ED jewel.

So, whereagles, I do apologize for my rather harsh condemnation of Puls; it was moderately unfounded. However, I still hold that there are better options, namely pure +% ED socket fillers, since they're effective against all monsters, not just Demons.

(also, it's easier to adapt your build to add more external +% ED than weapon +% ED, ie, more +skills, higher strength, et cetera)