I just started playing with these guys in SP, and might play them in an MP game. You lose some stuff from EA and MA, but you also gain a whole lot.
Good
Sauromancers are sacred!!
You get decent damage shielded infantry.
You can actually cast summon Scorpion Man!
You can summon reanimating priests!
All Sauromancers can cast Banefire!
Bad
No more nature or astral without pretender.
No more water.
No more predator lizards.
You still don't have any decent sacreds.
You don't have any high att units, or units with multiple attacks.
Even though they're cap only, I really liked the Desert Rangers for expansion after the first couple provs around your capital.
The tomb priests and kings sound cool, but I'm leery of shelling out that many D gems for a few reanimaters, especially when the tomb kings can't cast the H4 national spell. However, the 0 enc lizard chariots look pretty badass. Another problem though is that C'tis undead seems to be even crappier than the average, usually lacking armor and being armed with low dmg spears.
Just messing around, I took an awake dom 9 E9 Cyclops with O3 S1 H3 Mis 2 and D2. I got excellent expansion, though I hired some mercs to help me out, and my cyclops gives me access to all those nice endgame earth spells

What do you guys think?