This part of my 8th Edition Genestealer Cults codex review will take a look at the Elites section. The Cult got a lot of new support characters, who mostly reside here, along with the classic units.
I never tended to run these guys in the Index. They seemed to be very expensive for what they could do.
They Hybrid Metamorphs have a pretty strong profile. They are similar to Acolyte Metamorphs, but get 3 attacks base, one more than the Acolytes (though with their Cultist Knives, it adds up to the same, but without the weapons bonuses).
Where the squad gets their difference is in the metamorph upgrades they can take. They come with a Rending Claw and Metamorph Talon as standard, for 10 points per model. This gives them three attacks with the Rending Claw and one with the Talon (at S4 and AP0). This gives the squad four attacks as standard, which is pretty good for the unit, though I'm not sure the extra attack is worth 3 pts per model over the Acolyte Hybrids. The Talon also gives +1 to hit, which is a nice bonus, but you lose the AP.
They can also take a Metamorph Claw, taking them up to S6 and AP-1. This is pricey, taking them up to 13 pts per model. S6 is pretty good on the squad, with 3 attacks each at AP-1, they should do a lot of damage to a number of units. Again, I'm not sure this is worth it over the Heavy Mining Combat weapons the Acolyte Hybrids can take.
The can also replace their rending claw with a Metamorph talon. this takes them up to 11 pts each, but each Hybrid Metamorph then gets 5 attacks in combat (though at no AP). This is actually a pretty strong option against horde armies with poor armour saves, such as Orks or Guardsmen (or other Genestealer Cults armies!). All the attacks also get +1 to hit, allowing them to hit on a 2+ in most cases.
They can also take Metamorph whips, allowing them to strike again if they are slain.
I think the double Talons is a good option. A squad of 10 will get 50 attacks that hit on a 2+ at S4 for only 110 pts. That is pretty strong for going through horde units and weakly armoured enemy units. Throw on Might From Beyond to take them to S5 and 6 attacks each, and even vehicles may be threatened by this unit.
I think the Metamorphs have improved a bit over the index from getting cheaper. They can easily put out a lot of low AP attacks and should be able to do a lot of damage against selected enemy units. They still suffer from the poor durability of the Genestealer Cults units though, so will be easy to take out with enemy firepower.