I haven't seen the Ivomec cubes here but then I haven't looked for them either.
We use the Noromectin, because it is a fair bit cheaper than the Ivomec (or at least it was, Ivomec may have reduced their price now too, I'm not sure about that) and it works just the same. It too is 1 cc per 100 lbs, given orally.
I don't think that the Noromectin tastes as bad as, for instance, Banamine. Used to be there were paste dewormers that, after the horses got their dose, some of them would refuse to eat oats or anything for a little while afterward--it tasted yucky enough and the taste lingered long enough that they thought the offered oats contained more of the same! The Noromectin (or Ivomec) is much easier to give than the paste dewormers.
I find that with paste, if the horse has any bit of food hidden in his mouth it is likely to be spit out with a good portion of the paste stuck to it. With the liquid--that doesn't happen. Even if there is a bit of food in the mouth it usually doesn't get spit out after the dewormer is squirted into the mouth. Another benefit--in cold weather, the paste often gets too firm & is 1) harder to get out of the syringe and 2) is more likely to get spit out because it is too cold to stick to the mouth. Even when cold the liquid is easy to squirt out of the syringe, and it still adheres well to the tongue & mouth. It has a rather oily consistancy so it coats the tongue & doesn't come back out once it goes in.