Crap, I just had a long post deleted by a computer crash, even though I had copied to clipboard it was all lost.
The upshot was that there is a mid-21.7 ceiling for possibly clean women (just like that 9.8 ceiling for possibly clean men) and that the best-ever adjusted 200m likely legitimate times are:
1 Cuthbert 21.75
2 Felix 21.78
3 Campbell-Brown 21.79
4 Brisco-Hooks 21.81
4 Ashford 21.81
6 Jackson 21.82
This takes into account both known dopers and certain dopers. Of the top-13 unadjusted times, 7 are VERY questionable, leaving 6. Of those 6, 2 are generally questioned, leaving 4. Add in the 21.8-bubble athletes Ashford and Brisco-Hooks, and you are left with 6 performances. Anything below 21.7 is bogus.
Now that is a list I can believe, and by that list, Felix's run was one of the best-ever possibly legitimate runs. Add in the fact that it was run in not-perfect weather, and it could have been the best-ever if she had been able to go .03-.04 faster, which might be reasonable.
As far as her RT goes, it was average for the field in that race, so a better RT can't reasonably be expected to have happened. Maybe had the race been elsewhere, the RT's would have been faster, who knows. Ultimately, this was an amazing run by Felix, and believable--hats off.
Will she get the absolute WR clean? No. It is miles away.