Olympic lowers are usually cast Aluminum.
Stag are forged.
Olympic is a lower teir manufacture that builds rifles with parts that did not make the QC cut from other manufacturers.
Stag is definitley an upper teir manufacture with first class fit, finish and parts.

No brainer

Check out the charts in this link. Kind of a PITA but if you take the time to read it and look through the charts it will tell alot! Use the tabs at the bottom of the sheet to navigate through the page.

http://http://spreadsheets.google.co...jFwPrgTA&hl=en