Arrow, i'm a little confused. I fly with Cranium and the parts a little different.
I have the dynam shafts (which are great) but kinda seem to come a little bent from bphobbies I have not addressed this issue with him. The gears are a little lopsided. I've seen Cranium's extreme core and the gear rides on a straight plane with the pinion. This doesn't seem to cause a flight issue though and i agree the cost is MUCH CHEAPER with vortex parts. However...

Shipping from the place where cranium gets his cores is CHEAP which may negate the price savings...i'm out calculating now.

The upper head for vortex is different shape than the upper head for extreme core. I don't want to spend more money testing, but i bet it is the Esky upper head. The picture on bp's site makes it look the same.

The lower rotor head for the vortex has incorrect linkages to work with the blade cx2 swashplates (MH)

Where can i find the correct linkage which comes with extreme core? Is this also a repackaged esky piece? I would much rather have lighter plastic grips than the Xtreme alum (which look great and i hear fly great) but the plastic extreme core flys very quiet and stable.

I'm all for saving money, but they now sell it with 8 bladees making the cost pretty spot on. I agree the vortex blade grips are a little different in shape than extreme core...maybe they are really the esky grips?

Until i find a linkage...i'm on stock blades. I think i'm going to order the Xtreme from USHobby when he gets the new version instock.

Done rambling...i'm quiet...i'll post more! (i'm the pusher who got Cranium started)