I've never been charged more than $500 by now. Cant say if it goes up to $900 would I change my mind or not.
140K on a *A partner with UA miles includes $100 something charges as well.

It boils down to your individual situation:
VIE-ORD roundtrip was 55k+$500 last spring on OS vs. UAL for 140k roundtrip.
For newbies like me without loads of UA miles (or loads of credit card points), the previous option enables me to burn miles faster, plus a better biz product.