B -
A few of my students are using the 840's and like them. I have no idea what Hoyt is doing with the Satori so can't make a comparison. I advise most people against current issue Hoyt limbs as a general rule. You'll do better with the Chinese/Korean offerings in price, performance and in a lot of cases durability.
For a pure training limb, you're not going the beat the SF Axiom Plus or Galaxy limbs in the same, <$100 price range.
Viper out.