"so stellar" is a correct and usable phrase in written English.
You can use it to emphasize something as being exceptionally good or impressive. For example, "She did an amazing job on the project - her work was simply so stellar!".
Azarenka's record against Williams is not so stellar.
But the performance outside its home market was not so stellar.
Given that this year's stock market performance has been so stellar, most investors are probably pretty content.
I'm not sure I've ever seen so many books and manuscripts out in the East Room before and certainly never so stellar a selection.
"Also, because the show was so stellar on so many levels, we decided to take a chance to bring it back at any cost".
8.06am GMT In a similar theme... Constantin Gurdgiev (@GTCost) So stellar performance of France in 2012 = 0% GDP growth, 2013=0.3% GDP growth y/y.
After a disastrous launch and a not-so stellar pivot, Color may finally have found its stride and a rather large core user base.
Throughout their 30-year marriage, Paul and Linda McCartney produced some stellar work (their daughter Stella, for example) and some not-so-stellar work (Off the Ground).
After working in minor visiting positions and fellowships, I got a tenure-line position at a not-so-stellar private university.
After all, this is the preseason, one in which Camby's not-so-stellar cast of opposing starters has included Michael Ruffin of the Chicago Bulls, Jahidi White of the Washington Wizards and Joel Pryzbilla of the Milwaukee Bucks.
"I mean, who wants a gay wedding menu?" DAN BILEFSKY At First, Idle Judges Despite the evident pride of officials volunteering at the Bronx marriage bureau, many of whom spoke of the historic occasion, the bureau — which has been faulted for bureaucratic lapses in the past — lived up to its not-so-stellar reputation.
