I think OP was pretty clear that he would like non-stop flights. SEA is pretty far out of the way to get between SFO and DFW. If he's going to connect, might as well use DL metal and go through SLC. Also, as a DL Gold the upgrade chances on DL metal flights through SLC will be much better than on AS metal through SEA.
if OP wants the miles, then its an option, I sure as hell would do the connection over the non stop for the miles