diff. is in the bottom metal, and depending on "grade" of rifle, the finsh
I use ADL's a lot, as i'm going to true anyway,and re-do finish, and often use PTG bottom metal
The carbon steel actions are cheaper but they're out of stock at Bud's right now. I would always choose a stainless action if I had the choice however. You might be able to find an ADL cheaper and part it out for the action, but you've still got a blued action instead of stainless. The parts left over after you strip apart a M700 ADL pretty much aren't worth the trouble to sell them on Ebay.