The 22 creedmore is specified with a 1:8 twist and can stabilize the 80gr but not the 88gr bullets.
The BC on the 22 cal 88gr ELD-M is better than the BC on the 6mm 108gr ELD-M.
The 22 ARC is "loaded down" for Gass guns but you can get another 150 fps if handloading. (For the record, I do not hand load, but I would like to in the future.)
The 22 Creedmoor will have a lesser barrel life than the 22 ARC and currently the ammo is only being sold through Horizon Firearms as they have exclusive rights at the moment and availability is hit/miss. The 22 ARC has been available at every local shop I have walked in lately.
The 22 creedmore ammo is running $2 per round. I can find (with very little searching) 22 ARC at $1.35 to $1.50 per round between the local shops or online with shipping.
I have no interest in a gas gun as I would want to save the brass and I have yet to find a good brass catcher that is effective, quiet and simple. With that being said, if I decided I was wrong and went that direction, I would rather an AR15 platform over the heavier AR10 platform.
There is my thesis and justification why I need to build a 22 ARC! If only the budget would understand and loosen the purse strings! This is the plan over the next few months anyhow.